Add features to typst base template.

This implements the changes suggested in #9956, with the exception of
the filecolor/urlcolor one. These would require adding some regex to
guess the link types. This is theoretically possible to do, but it
wasn't clear to me that this is a good thing to put in a default
template. Happy to adjust if you have thoughts on this.

Closes #9956.

Some things to note:

I'm converting colors by passing them as content, as I was seeing pandoc
escape # if that was included.

I set the default fonts for math and code ("raw") to fonts that are
bundled with Typst. These need not be those fonts if there are more
familiar pandoc preferences.

4 files changed, 165 insertions, 75 deletions

diff --git a/MANUAL.txt b/MANUAL.txt
index 39355c424..7ee20e59a 100644
--- a/MANUAL.txt
+++ b/MANUAL.txt
@@ -2728,7 +2728,7 @@ Currently the following pipes are predefined:
     documents
 
 `abstract-title`
-:   title of abstract, currently used only in HTML, EPUB, and docx.
+:   title of abstract, currently used only in HTML, EPUB, docx, and Typst.
     This will be set automatically to a localized value,
     depending on `lang`, but can be manually overridden.
 
@@ -3391,6 +3391,19 @@ The `--css` option also affects the output.
 `columns`
 :    Number of columns for body text.
 
+`thanks`
+:   contents of acknowledgments footnote after document title
+
+`mathfont`, `codefont`
+:    Name of system font to use for math and code, respectively.
+
+`linestretch`
+:   adjusts line spacing, e.g. `1.25`, `1.5`
+
+`linkcolor`, `filecolor`, `citecolor`
+:   color for external links, internal links, and citation links,
+    respectively: expects a hexadecimal color code
+
 ### Variables for ms
 
 `fontfamily`
diff --git a/data/templates/default.typst b/data/templates/default.typst
index 79b2c33f5..00e1ec557 100644
--- a/data/templates/default.typst
+++ b/data/templates/default.typst
@@ -71,9 +71,15 @@ $endif$
 $if(region)$
   region: "$region$",
 $endif$
+$if(abstract-title)$
+  abstract-title: [$abstract-title$],
+$endif$
 $if(abstract)$
   abstract: [$abstract$],
 $endif$
+$if(thanks)$
+  thanks: [$thanks$],
+$endif$
 $if(margin)$
   margin: ($for(margin/pairs)$$margin.key$: $margin.value$,$endfor$),
 $endif$
@@ -86,10 +92,28 @@ $endif$
 $if(fontsize)$
   fontsize: $fontsize$,
 $endif$
+$if(mathfont)$
+  mathfont: ($for(mathfont)$"$mathfont$",$endfor$),
+$endif$
+$if(codefont)$
+  codefont: ($for(codefont)$"$codefont$",$endfor$),
+$endif$
+$if(linestretch)$
+  linestretch: $linestretch$,
+$endif$
 $if(section-numbering)$
   sectionnumbering: "$section-numbering$",
 $endif$
   pagenumbering: $if(page-numbering)$"$page-numbering$"$else$none$endif$,
+$if(linkcolor)$
+  linkcolor: [$linkcolor$],
+$endif$
+$if(citecolor)$
+  citecolor: [$citecolor$],
+$endif$
+$if(filecolor)$
+  filecolor: [$filecolor$],
+$endif$
   cols: $if(columns)$$columns$$else$1$endif$,
   doc,
 )
diff --git a/data/templates/template.typst b/data/templates/template.typst
index 24b1320fb..1afaa35fc 100644
--- a/data/templates/template.typst
+++ b/data/templates/template.typst
@@ -15,7 +15,9 @@
   authors: (),
   keywords: (),
   date: none,
+  abstract-title: none,
   abstract: none,
+  thanks: none,
   cols: 1,
   margin: (x: 1.25in, y: 1.25in),
   paper: "us-letter",
@@ -23,66 +25,90 @@
   region: "US",
   font: (),
   fontsize: 11pt,
+  mathfont: none,
+  codefont: none,
+  linestretch: 1,
   sectionnumbering: none,
+  linkcolor: none,
+  citecolor: none,
+  filecolor: none,
   pagenumbering: "1",
   doc,
 ) = {
   set document(
     title: title,
-    author: authors.map(author => content-to-string(author.name)),
+    author: authors.map(author => content-to-string(author.name)).join(", ", last: " & "),
     keywords: keywords,
   )
   set page(
     paper: paper,
     margin: margin,
     numbering: pagenumbering,
-    columns: cols,
-    )
-  set par(justify: true)
+  )
+
+  set par(
+    justify: true,
+    leading: linestretch * 0.65em
+  )
   set text(lang: lang,
            region: region,
            font: font,
            size: fontsize)
+
+  show math.equation: set text(font: mathfont) if mathfont != none
+  show raw: set text(font: codefont) if codefont != none
+
   set heading(numbering: sectionnumbering)
 
-  place(top, float: true, scope: "parent", clearance: 4mm)[
-  #if title != none {
-    align(center)[#block(inset: 2em)[
-      #text(weight: "bold", size: 1.5em)[#title]
-      #(if subtitle != none {
-        parbreak()
-        text(weight: "bold", size: 1.25em)[#subtitle]
-      })
-    ]]
+  show link: set text(fill: rgb(content-to-string(linkcolor))) if linkcolor != none
+  show ref: set text(fill: rgb(content-to-string(citecolor))) if citecolor != none
+  show link: this => {
+    if filecolor != none and type(this.dest) == label {
+      text(this, fill: rgb(content-to-string(filecolor)))
+    }
   }
 
-  #if authors != none and authors != [] {
-    let count = authors.len()
-    let ncols = calc.min(count, 3)
-    grid(
-      columns: (1fr,) * ncols,
-      row-gutter: 1.5em,
-      ..authors.map(author =>
-          align(center)[
-            #author.name \
-            #author.affiliation \
-            #author.email
-          ]
+  block(below: 4mm)[
+    #if title != none {
+      align(center)[#block(inset: 2em)[
+          #text(weight: "bold", size: 1.5em)[#title #if thanks != none {
+              footnote(thanks, numbering: "*")
+              counter(footnote).update(n => n - 1)
+            }]
+          #(
+            if subtitle != none {
+              parbreak()
+              text(weight: "bold", size: 1.25em)[#subtitle]
+            }
+          )
+        ]]
+    }
+
+    #if authors != none and authors != [] {
+      let count = authors.len()
+      let ncols = calc.min(count, 3)
+      grid(
+        columns: (1fr,) * ncols,
+        row-gutter: 1.5em,
+        ..authors.map(author => align(center)[
+          #author.name \
+          #author.affiliation \
+          #author.email
+        ])
       )
-    )
-  }
+    }
 
-  #if date != none {
-    align(center)[#block(inset: 1em)[
-      #date
-    ]]
-  }
+    #if date != none {
+      align(center)[#block(inset: 1em)[
+          #date
+        ]]
+    }
 
-  #if abstract != none {
-    block(inset: 2em)[
-    #text(weight: "semibold")[$if(abstract-title)$${abstract-title}$else$Abstract$endif$] #h(1em) #abstract
-    ]
-  }
+    #if abstract != none {
+      block(inset: 2em)[
+        #text(weight: "semibold")[#abstract-title] #h(1em) #abstract
+      ]
+    }
   ]
 
   doc
diff --git a/test/writer.typst b/test/writer.typst
index 5ff3051d4..5521680c7 100644
--- a/test/writer.typst
+++ b/test/writer.typst
@@ -39,7 +39,9 @@
   authors: (),
   keywords: (),
   date: none,
+  abstract-title: none,
   abstract: none,
+  thanks: none,
   cols: 1,
   margin: (x: 1.25in, y: 1.25in),
   paper: "us-letter",
@@ -47,66 +49,90 @@
   region: "US",
   font: (),
   fontsize: 11pt,
+  mathfont: none,
+  codefont: none,
+  linestretch: 1,
   sectionnumbering: none,
+  linkcolor: none,
+  citecolor: none,
+  filecolor: none,
   pagenumbering: "1",
   doc,
 ) = {
   set document(
     title: title,
-    author: authors.map(author => content-to-string(author.name)),
+    author: authors.map(author => content-to-string(author.name)).join(", ", last: " & "),
     keywords: keywords,
   )
   set page(
     paper: paper,
     margin: margin,
     numbering: pagenumbering,
-    columns: cols,
-    )
-  set par(justify: true)
+  )
+
+  set par(
+    justify: true,
+    leading: linestretch * 0.65em
+  )
   set text(lang: lang,
            region: region,
            font: font,
            size: fontsize)
+
+  show math.equation: set text(font: mathfont) if mathfont != none
+  show raw: set text(font: codefont) if codefont != none
+
   set heading(numbering: sectionnumbering)
 
-  place(top, float: true, scope: "parent", clearance: 4mm)[
-  #if title != none {
-    align(center)[#block(inset: 2em)[
-      #text(weight: "bold", size: 1.5em)[#title]
-      #(if subtitle != none {
-        parbreak()
-        text(weight: "bold", size: 1.25em)[#subtitle]
-      })
-    ]]
+  show link: set text(fill: rgb(content-to-string(linkcolor))) if linkcolor != none
+  show ref: set text(fill: rgb(content-to-string(citecolor))) if citecolor != none
+  show link: this => {
+    if filecolor != none and type(this.dest) == label {
+      text(this, fill: rgb(content-to-string(filecolor)))
+    }
   }
 
-  #if authors != none and authors != [] {
-    let count = authors.len()
-    let ncols = calc.min(count, 3)
-    grid(
-      columns: (1fr,) * ncols,
-      row-gutter: 1.5em,
-      ..authors.map(author =>
-          align(center)[
-            #author.name \
-            #author.affiliation \
-            #author.email
-          ]
+  block(below: 4mm)[
+    #if title != none {
+      align(center)[#block(inset: 2em)[
+          #text(weight: "bold", size: 1.5em)[#title #if thanks != none {
+              footnote(thanks, numbering: "*")
+              counter(footnote).update(n => n - 1)
+            }]
+          #(
+            if subtitle != none {
+              parbreak()
+              text(weight: "bold", size: 1.25em)[#subtitle]
+            }
+          )
+        ]]
+    }
+
+    #if authors != none and authors != [] {
+      let count = authors.len()
+      let ncols = calc.min(count, 3)
+      grid(
+        columns: (1fr,) * ncols,
+        row-gutter: 1.5em,
+        ..authors.map(author => align(center)[
+          #author.name \
+          #author.affiliation \
+          #author.email
+        ])
       )
-    )
-  }
+    }
 
-  #if date != none {
-    align(center)[#block(inset: 1em)[
-      #date
-    ]]
-  }
+    #if date != none {
+      align(center)[#block(inset: 1em)[
+          #date
+        ]]
+    }
 
-  #if abstract != none {
-    block(inset: 2em)[
-    #text(weight: "semibold")[Abstract] #h(1em) #abstract
-    ]
-  }
+    #if abstract != none {
+      block(inset: 2em)[
+        #text(weight: "semibold")[#abstract-title] #h(1em) #abstract
+      ]
+    }
   ]
 
   doc
@@ -122,6 +148,7 @@
       email: "" ),
     ),
   date: [July 17, 2006],
+  abstract-title: [Abstract],
   pagenumbering: "1",
   cols: 1,
   doc,