fix: address code review findings and critical issues

Critical Fixes:
- Fixed EditorConfig violations in grammar.js, scanner.c, README.md, .mega-linter.yml
  - Changed JSDoc comments from 1-space to 2-space indent per .editorconfig
  - Fixed line length violations in README.md and .mega-linter.yml
- Updated test count badge from 59/59 to 61/61 in README.md
- Created queries/highlights.scm for syntax highlighting support
- Updated package.json with repository and files fields

Configuration Updates:
- Added repository field pointing to GitHub
- Added files field to control npm package contents
- Properly formatted CONTRIBUTING.md with prettier

All 61 tests passing (100% success rate)
All critical EditorConfig violations resolved

package.json

@@ -5,6 +5,18 @@
   "main": "grammar.js",
   "author": "Ismo Vuorinen",
   "license": "MIT",
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/ivuorinen/tree-sitter-shellspec.git"
+  },
+  "files": [
+    "grammar.js",
+    "src",
+    "queries",
+    "binding.gyp",
+    "bindings",
+    "scripts"
+  ],
   "scripts": {
     "generate": "tree-sitter generate && ./scripts/post-generate.sh",
     "generate:only": "tree-sitter generate",