use custom parser for gts/gjs

bonus:
 * enables type aware lints
 * prettier eslint plugin (with template tag prettier plugin) will just work for gts/gjs
 * can detect unused block params in templates
 * can detect undef vars in PathExpression
 * can add eslint directive comments in mustache or html
disadvantage:
* prettier will not work without template tag prettier plugin for gts/gjs files

Author: patricklx

README.md

@@ -42,6 +42,29 @@ module.exports = {
 };
 ```
 
+To correctly parse gjs/gts:
+Do not set an override for the parser in the global config.
+To use e.g. the typescript parser, the following should be used
+
+```js
+// .eslintrc.js
+module.exports = {
+  plugins: ['ember'],
+  // parser: '@typescript-eslint/parser', <-- needs to be removed, or set the gts/gjs one
+  // so we could also have:
+  // parser: "eslint-plugin-ember/gts-parser",
+  extends: [
+    'eslint:recommended',
+    'plugin:@typescript-eslint/base', // or typescript-eslint/recommended, must come before plugin:ember/recommended
+    'plugin:ember/recommended', // or other configuration
+  ],
+  rules: {
+    // override / enable optional rules
+    'ember/no-replace-test-comments': 'error'
+  }
+};
+```
+
 ## 🧰 Configurations
 
 |    | Name | Description |

lib/config/recommended.js

@@ -1,5 +1,4 @@
 const rules = require('../recommended-rules');
-const util = require('ember-template-imports/src/util');
 
 module.exports = {
   root: true,
@@ -29,11 +28,12 @@ module.exports = {
      * on -- and isn't relevant to user-land code.
      */
     {
-      files: ['**/*.gjs', '**/*.gts'],
-      processor: 'ember/<template>',
-      globals: {
-        [util.TEMPLATE_TAG_PLACEHOLDER]: 'readonly',
-      },
+      files: ['**/*.gts'],
+      parser: require.resolve('../parsers/gts-parser'),
+    },
+    {
+      files: ['**/*.gjs'],
+      parser: require.resolve('../parsers/gjs-parser'),
     },
   ],
 };

lib/index.js

@@ -2,18 +2,10 @@
 
 const requireIndex = require('requireindex');
 
-const gjs = require('./preprocessors/glimmer');
-
 module.exports = {
   rules: requireIndex(`${__dirname}/rules`),
   configs: requireIndex(`${__dirname}/config`),
   utils: {
     ember: require('./utils/ember'),
   },
-  processors: {
-    // https://eslint.org/docs/developer-guide/working-with-plugins#file-extension-named-processor
-    '.gjs': gjs,
-    '.gts': gjs,
-    '<template>': gjs,
-  },
 };