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/pony/highlights.scm

@@ -2,7 +2,7 @@
 
 [
   "use"
-] @include
+] @keyword.import
 
 ; Keywords
 
@@ -68,13 +68,13 @@
   "else"
   "elseif"
   "match"
-] @conditional
+] @keyword.conditional
 
-(if_statement "end" @conditional)
+(if_statement "end" @keyword.conditional)
 
-(iftype_statement "end" @conditional)
+(iftype_statement "end" @keyword.conditional)
 
-(match_statement "end" @conditional)
+(match_statement "end" @keyword.conditional)
 
 ; Repeats
 
@@ -86,11 +86,11 @@
   "continue"
   "do"
   "break"
-] @repeat
+] @keyword.repeat
 
-(do_block "end" @repeat)
+(do_block "end" @keyword.repeat)
 
-(repeat_statement "end" @repeat)
+(repeat_statement "end" @keyword.repeat)
 
 ; Exceptions
 
@@ -98,11 +98,11 @@
   "try"
   (error)
   "compile_error"
-] @exception
+] @keyword.exception
 
-(try_statement "end" @exception)
+(try_statement "end" @keyword.exception)
 
-(recover_statement "end" @exception)
+(recover_statement "end" @keyword.exception)
 
 ; Attributes
 
@@ -116,9 +116,9 @@
 
 ; Fields
 
-(field name: (identifier) @field)
+(field name: (identifier) @variable.member)
 
-(member_expression "." (identifier) @field)
+(member_expression "." (identifier) @variable.member)
 
 ; Constructors
 
@@ -126,11 +126,11 @@
 
 ; Methods
 
-(method (identifier) @method)
+(method (identifier) @function.method)
 
-(behavior (identifier) @method)
+(behavior (identifier) @function.method)
 
-(ffi_method (identifier) @method)
+(ffi_method (identifier) @function.method)
 
 ((ffi_method (string) @string.special)
   (#set! "priority" 105))
@@ -138,15 +138,15 @@
 (call_expression
   callee:
     [
-      (identifier) @method.call
-      (ffi_identifier (identifier) @method.call)
-      (member_expression "." (identifier) @method.call)
+      (identifier) @function.method.call
+      (ffi_identifier (identifier) @function.method.call)
+      (member_expression "." (identifier) @function.method.call)
     ])
 
 ; Parameters
 
-(parameter name: (identifier) @parameter)
-(lambda_parameter name: (identifier) @parameter)
+(parameter name: (identifier) @variable.parameter)
+(lambda_parameter name: (identifier) @variable.parameter)
 
 ; Types
 
@@ -156,7 +156,7 @@
 
 (generic_parameter (identifier) @type)
 
-(lambda_type (identifier)? @method)
+(lambda_type (identifier)? @function.method)
 
 ((identifier) @type
   (#lua-match? @type "^_*[A-Z][a-zA-Z0-9_]*$"))
@@ -250,7 +250,7 @@
 
 (number) @number
 
-(float) @float
+(float) @number.float
 
 (boolean) @boolean