Add additional examples and fix lint errors

Author: hxqlin

docs/rules/no-empty-glimmer-component-classes.md

@@ -31,4 +31,4 @@ class MyComponent extends Component {
 ## References
 
 * [Glimmer Components - Octane Upgrade Guide](https://guides.emberjs.com/release/upgrading/current-edition/glimmer-components/)
-* [Glimmer Components RFC](https://emberjs.github.io/rfcs/0416-glimmer-components.html)
+* [Glimmer Components RFC](https://emberjs.github.io/rfcs/0416-glimmer-components.html)

lib/rules/no-empty-glimmer-component-classes.js

@@ -15,7 +15,8 @@ module.exports = {
       description: 'disallow empty backing classes for Glimmer components',
       category: 'Ember Octane',
       recommended: false,
-      url: 'https://github.com/ember-cli/eslint-plugin-ember/tree/master/docs/rules/no-empty-glimmer-component-classes.md',
+      url:
+        'https://github.com/ember-cli/eslint-plugin-ember/tree/master/docs/rules/no-empty-glimmer-component-classes.md',
     },
     fixable: null,
     schema: [],

tests/lib/rules/no-empty-glimmer-component-classes.js

@@ -27,6 +27,7 @@ ruleTester.run('no-empty-glimmer-component-classes', rule, {
         return this.args.bar + this.args.baz;
       }
     }`,
+    'class MyComponent extends NotAGlimmerComponent {}',
   ],
   invalid: [
     {
@@ -36,5 +37,12 @@ ruleTester.run('no-empty-glimmer-component-classes', rule, {
       output: null,
       errors: [{ message: ERROR_MESSAGE, type: 'ClassDeclaration' }],
     },
+    {
+      code: `import Component from '@glimmer/component';
+
+      class MyComponent extends Component { /* foo */ }`,
+      output: null,
+      errors: [{ message: ERROR_MESSAGE, type: 'ClassDeclaration' }],
+    },
   ],
 });