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/cpp/highlights.scm

@@ -1,33 +1,33 @@
 ; inherits: c
 
-((identifier) @field
-  (#lua-match? @field "^m_.*$"))
+((identifier) @variable.member
+  (#lua-match? @variable.member "^m_.*$"))
 
 (parameter_declaration
-  declarator: (reference_declarator) @parameter)
+  declarator: (reference_declarator) @variable.parameter)
 
 ; function(Foo ...foo)
 (variadic_parameter_declaration
   declarator: (variadic_declarator
-                (_) @parameter))
+                (_) @variable.parameter))
 ; int foo = 0
 (optional_parameter_declaration
-    declarator: (_) @parameter)
+    declarator: (_) @variable.parameter)
 
-;(field_expression) @parameter ;; How to highlight this?
+;(field_expression) @variable.parameter ;; How to highlight this?
 
 (((field_expression
-     (field_identifier) @method)) @_parent
+     (field_identifier) @function.method)) @_parent
  (#has-parent? @_parent template_method function_declarator))
 
 (field_declaration
-  (field_identifier) @field)
+  (field_identifier) @variable.member)
 
 (field_initializer
  (field_identifier) @property)
 
 (function_declarator
-  declarator: (field_identifier) @method)
+  declarator: (field_identifier) @function.method)
 
 (concept_definition
   name: (identifier) @type.definition)
@@ -37,17 +37,17 @@
 
 (auto) @type.builtin
 
-(namespace_identifier) @namespace
+(namespace_identifier) @module
 ((namespace_identifier) @type
   (#lua-match? @type "^[%u]"))
 
 (case_statement
   value: (qualified_identifier (identifier) @constant))
 
-(using_declaration . "using" . "namespace" . [(qualified_identifier) (identifier)] @namespace)
+(using_declaration . "using" . "namespace" . [(qualified_identifier) (identifier)] @module)
 
 (destructor_name
-  (identifier) @method)
+  (identifier) @function.method)
 
 ; functions
 (function_declarator
@@ -125,10 +125,10 @@
 ; methods
 (function_declarator
   (template_method
-    (field_identifier) @method))
+    (field_identifier) @function.method))
 (call_expression
   (field_expression
-    (field_identifier) @method.call))
+    (field_identifier) @function.method.call))
 
 ; constructors
 
@@ -176,7 +176,7 @@
  "catch"
  "noexcept"
  "throw"
-] @exception
+] @keyword.exception
 
 
 [