feat!: align standard captures with upstream

Problem: Sharing highlight queries with upstream tree-sitter and
Helix is difficult.

Solution: Where reasonable, use capture names in tree-sitter's standard
list or Helix's Atom-style hierarchy.

Specifically:

* tree-sitter "standard capture names"
  (3f44b89685/highlight/src/lib.rs (L20-L72)):

  - `@parameter` -> `@variable.parameter`
  - `@field` -> `@variable.member`
  - `@namespace` -> `@module`
  - `@float` -> `@number.float`
  - `@symbol` -> `@string.special.symbol`
  - `@string.regex` -> `@string.regexp`
  - `@text.*` -> `@markup.*` (`strong`, `italic`, `link`, `strikethrough`; with exceptions; see below)
  - `@text.title` -> `@markup.heading`
  - `@text.literal` -> `@markup.raw`
  - `@text.reference` -> `@markup.link`
  - `@text.uri` -> `@markup.link.url` (in markup links)
  - `@string.special` -> `@markup.link.label` (non-url links)
  - `@punctuation.special` -> `@markup.list` (markdown lists only; move subitems from `@text.todo`)

* Helix captures
  (https://docs.helix-editor.com/master/themes.html#syntax-highlighting):

  - `@method` -> `@function.method`
  - `@method.call` -> `@function.method.call`
  - `@text.{todo,warning,note,danger}` -> `@comment.{error,warning,hint,info,todo}`
  - `@text.diff.{add,delete,}` -> `@diff.{plus,minus,delta}`
  - `@text.uri` -> `@string.special.url` (outside markup)
  - `@preproc` -> `@keyword.directive`
  - `@define` -> `@keyword.directive`(`.define`?)
  - `@storageclass` -> `@keyword.storage`
  - `@conditional` -> `@keyword.conditional`
  - `@debug` -> `@keyword.debug`
  - `@exception` -> `@keyword.exception`
  - `@include` -> `@keyword.import`
  - `@repeat` -> `@keyword.repeat`

* cleanup

  - remove some redundant `@conceal` (but still allow it for conceal-only patterns)
  - remove obsolete `@error` (syntax linting is out of scope for this repo)
  - sort, cleanup capture list in `CONTRIBUTING.md`

queries/rst/highlights.scm

@@ -7,11 +7,13 @@
   "__"
   ":"
   "::"
-  "bullet"
-  "adornment"
   (transition)
 ] @punctuation.special
 
+[
+  "bullet"
+  "adornment"
+] @markup.list
 ;; Resets for injection
 
 (doctest_block) @none
@@ -22,11 +24,11 @@
   name: (type) @function)
 
 (directive
-  body: (body (arguments) @parameter))
+  body: (body (arguments) @variable.parameter))
 
 ((directive
-  name: (type) @include)
- (#eq? @include "include"))
+  name: (type) @keyword.import)
+ (#eq? @keyword.import "include"))
 
 ((directive
    name: (type) @function.builtin)
@@ -48,10 +50,10 @@
 [
   (literal_block)
   (line_block)
-] @text.literal
+] @markup.raw.block
 
 (block_quote
-  (attribution)? @text.emphasis) @text.literal
+  (attribution)? @markup.italic) @markup.quote
 
 (substitution_definition
   name: (substitution) @constant)
@@ -63,26 +65,26 @@
   name: (label) @constant)
 
 (target
-  name: (name)? @constant
-  link: (_)? @text.literal)
+  name: (name)? @markup.link.label
+  link: (_)? @markup.link)
 
 ;; Lists
 
 ; Definition lists
 (list_item
-  (term) @text.strong
-  (classifier)? @text.emphasis)
+  (term) @markup.strong
+  (classifier)? @markup.italic)
 
 ; Field lists
 (field (field_name) @constant)
 
 ;; Inline markup
 
-(emphasis) @text.emphasis
+(emphasis) @markup.italic
 
-(strong) @text.strong
+(strong) @markup.strong
 
-(standalone_hyperlink) @text.uri @nospell
+(standalone_hyperlink) @string.special.url @nospell
 
 (role) @function
 
@@ -111,17 +113,17 @@
 [
  "interpreted_text"
   (literal)
-] @text.literal
+] @markup.raw
 
 ; Prefix role
 ((interpreted_text
   (role) @_role
-  "interpreted_text" @text.emphasis)
+  "interpreted_text" @markup.italic)
  (#eq? @_role ":emphasis:"))
 
 ((interpreted_text
   (role) @_role
-  "interpreted_text" @text.strong)
+  "interpreted_text" @markup.strong)
  (#eq? @_role ":strong:"))
 
 ((interpreted_text
@@ -131,12 +133,12 @@
 
 ; Suffix role
 ((interpreted_text
-  "interpreted_text" @text.emphasis
+  "interpreted_text" @markup.italic
   (role) @_role)
  (#eq? @_role ":emphasis:"))
 
 ((interpreted_text
-  "interpreted_text" @text.strong
+  "interpreted_text" @markup.strong
   (role) @_role)
  (#eq? @_role ":strong:"))
 
@@ -151,11 +153,11 @@
   (footnote_reference)
   (citation_reference)
   (reference)
-] @text.reference @nospell
+] @markup.link @nospell
 
 ;; Others
 
-(title) @text.title
+(title) @markup.heading
 
 (comment) @comment @spell
 (comment "..") @comment