feat(editor): highlight tags inside doc comments (#2200)

Tags inside doc comments looked like the rest of the comment text. They now get their own colours in Java, Kotlin, JavaScript, TypeScript, JSX, TSX and PHP: block and inline tags, tag values such as a `@param` name, KDoc links, and HTML markup from a fixed element list. Plain comments, strings and an `@` inside text get nothing. Colours come from new theme tokens, with entries under Settings > Editor > Color Scheme, in every built-in theme, and through .icls and IntelliJ theme import.

Only comment nodes in the visible ranges are scanned. The Kotlin tokenizer records doc comment state in its parser state, so long comments stay fast and correct.

Co-authored-by: lleviathe <[email protected]>

docs/plugins/themes.md

@@ -221,6 +221,7 @@ The full table is `UI_KEYS` in [`src/features/plugins/intellijTheme.ts`](../../s
 | `--vcs-*`, `--gutter-*` | colour `FILESTATUS_*`, `MODIFIED_LINES_COLOR`, `ADDED_LINES_COLOR`, `DELETED_LINES_COLOR` |
 | `--syn-keyword`, `--syn-string`, `--syn-number` | `DEFAULT_KEYWORD`, `DEFAULT_STRING`, `DEFAULT_NUMBER` |
 | `--syn-comment` (+ `--syn-comment-style`), `--syn-doc-comment` | `DEFAULT_LINE_COMMENT` (+ `FONT_TYPE`), `DEFAULT_DOC_COMMENT` |
+| `--syn-doc-comment-tag`, `--syn-doc-comment-tag-value`, `--syn-doc-markup` (+ `-bg`) | `DEFAULT_DOC_COMMENT_TAG`, `DEFAULT_DOC_COMMENT_TAG_VALUE`, `DEFAULT_DOC_MARKUP` |
 | `--syn-function`, `--syn-function-call` | `DEFAULT_FUNCTION_DECLARATION`, `DEFAULT_FUNCTION_CALL` |
 | `--syn-type`, `--syn-constant`, `--syn-property` | `DEFAULT_CLASS_NAME`, `DEFAULT_CONSTANT`, `DEFAULT_INSTANCE_FIELD` |
 | `--syn-variable`, `--syn-param`, `--syn-builtin` | `DEFAULT_LOCAL_VARIABLE`, `DEFAULT_PARAMETER`, `DEFAULT_PREDEFINED_SYMBOL` |
@@ -328,7 +329,7 @@ a token.
 
 <!-- BEGIN GENERATED TOKEN REFERENCE: pnpm gen:theme-docs -->
 
-247 themeable tokens: 125 in the UI theme file, 122 in the editor colour scheme file.
+252 themeable tokens: 125 in the UI theme file, 127 in the editor colour scheme file.
 
 ### Surfaces (UI theme)
 
@@ -428,6 +429,11 @@ a token.
 | `--syn-comment` | `#7a7e85` | `#8c8c8c` |
 | `--syn-comment-style` | `normal` | `italic` |
 | `--syn-doc-comment` | `#5f826b` | `#8c8c8c` |
+| `--syn-doc-comment-tag` | `#67a37c` | `#8c8c8c` |
+| `--syn-doc-comment-tag-effect` | `none` | `underline #999999` |
+| `--syn-doc-comment-tag-value` | `#abadb3` | `#3d3d3d` |
+| `--syn-doc-markup` | `#68a67e` | `#8c8c8c` |
+| `--syn-doc-markup-bg` | `transparent` | `#e2ffe2` |
 | `--syn-docstring` | `#5f826b` | `#067d17` |
 | `--syn-annotation` | `#b3ae60` | `#9e880d` |
 | `--syn-decorator` | `#b3ae60` | `#9e880d` |