fix(highlight): link more treesitter groups by default (#20711)

Problem: Captures used by bundled parsers are not highlighted by default
Solution: Add links to default groups

A link is added for a capture if
* there is a default group of the same name (e.g., `@tag` -> `Tag`)
* it's used in a bundled query and doesn't have a reasonable fallback
  (e.g., `@text.literal`)

Also add all linked groups to the treesitter docs.

runtime/doc/treesitter.txt

@@ -371,6 +371,59 @@ instance, to highlight comments differently per language: >
     hi @comment.c guifg=Blue
     hi @comment.lua @guifg=DarkBlue
     hi link @comment.doc.java String
+<
+The following captures are linked by default to standard |group-name|s:
+>
+    @text.literal      Comment
+    @text.reference    Identifier
+    @text.title        Title
+    @text.uri          Underlined
+    @text.underline    Underlined
+    @text.todo         Todo
+
+    @comment           Comment
+    @punctuation       Delimiter
+
+    @constant          Constant
+    @constant.builtin  Special
+    @constant.macro    Define
+    @define            Define
+    @macro             Macro
+    @string            String
+    @string.escape     SpecialChar
+    @string.special    SpecialChar
+    @character         Character
+    @character.special SpecialChar
+    @number            Number
+    @boolean           Boolean
+    @float             Float
+
+    @function          Function
+    @function.builtin  Special
+    @function.macro    Macro
+    @parameter         Identifier
+    @method            Function
+    @field             Identifier
+    @property          Identifier
+    @constructor       Special
+
+    @conditional       Conditional
+    @repeat            Repeat
+    @label             Label
+    @operator          Operator
+    @keyword           Keyword
+    @exception         Exception
+
+    @variable          Identifier
+    @type              Type
+    @type.definition   Typedef
+    @storageclass      StorageClass
+    @structure         Structure
+    @namespace         Identifier
+    @include           Include
+    @preproc           PreProc
+    @debug             Debug
+    @tag               Tag
 <
                                                   *treesitter-highlight-spell*
 The special `@spell` capture can be used to indicate that a node should be

src/nvim/highlight_group.c

@@ -98,8 +98,6 @@ enum {
 
 // The default highlight groups.  These are compiled-in for fast startup and
 // they still work when the runtime files can't be found.
-//
-// When making changes here, also change runtime/colors/default.vim!
 
 static const char *highlight_init_both[] = {
   "Conceal      ctermbg=DarkGrey ctermfg=LightGrey guibg=DarkGrey guifg=LightGrey",
@@ -186,9 +184,13 @@ static const char *highlight_init_both[] = {
   "default link DiagnosticSignInfo DiagnosticInfo",
   "default link DiagnosticSignHint DiagnosticHint",
 
+  // Text
+  "default link @text.literal Comment",
+  "default link @text.reference Identifier",
+  "default link @text.title Title",
+  "default link @text.uri Underlined",
   "default link @text.underline Underlined",
-  "default link @todo Todo",
+  "default link @text.todo Todo",
-  "default link @debug Debug",
 
   // Miscs
   "default link @comment Comment",
@@ -202,6 +204,7 @@ static const char *highlight_init_both[] = {
   "default link @macro Macro",
   "default link @string String",
   "default link @string.escape SpecialChar",
+  "default link @string.special SpecialChar",
   "default link @character Character",
   "default link @character.special SpecialChar",
   "default link @number Number",
@@ -226,12 +229,16 @@ static const char *highlight_init_both[] = {
   "default link @keyword Keyword",
   "default link @exception Exception",
 
+  "default link @variable Identifier",
   "default link @type Type",
   "default link @type.definition Typedef",
   "default link @storageclass StorageClass",
   "default link @structure Structure",
+  "default link @namespace Identifier",
   "default link @include Include",
   "default link @preproc PreProc",
+  "default link @debug Debug",
+  "default link @tag Tag",
   NULL
 };