fix: resolve documentation inconsistencies and add ExampleGroup variants

Documentation Fixes:
- README.md: Update test count from 59 to 63 (badge, features, test command)
- README.md: Fix lint script references to actual npm scripts
- CONTRIBUTING.md: Correct format script reference to npm run format:check
- package.json: Remove non-existent yamllint script, split lint:markdown into check/fix variants

Grammar Enhancements:
- Add fExampleGroup and xExampleGroup to Context block variants
- Regenerate parser with new grammar (63/63 tests passing, 100% success rate)

Syntax Highlighting:
- Add fExampleGroup and xExampleGroup to focused/skipped block highlights
- Remove non-matching Data modifier tokens (:raw, :expand, #|)
- Add "End" keyword as block terminator

Memory File Corrections:
- Remove incorrect merge_group trigger references
- Remove pr-lint.yml workflow references (deleted in previous optimization)
- Update test counts with timestamps (59→63, added 2025-12-11)
- Update conflict count (13→5, optimized)

Code Style:
- Auto-format renovate.json and tree-sitter.json with prettier

src/node-types.json

@@ -3143,6 +3143,10 @@
     "type": "fExample",
     "named": false
   },
+  {
+    "type": "fExampleGroup",
+    "named": false
+  },
   {
     "type": "fIt",
     "named": false
@@ -3271,6 +3275,10 @@
     "type": "xExample",
     "named": false
   },
+  {
+    "type": "xExampleGroup",
+    "named": false
+  },
   {
     "type": "xIt",
     "named": false
@@ -3307,4 +3315,4 @@
     "type": "~",
     "named": false
   }
-]
+]