Migrated from TSLint to ESLint.

See:

 - angular-eslint/angular-eslint#89 (comment)
 - angular-eslint/angular-eslint#86 (comment)
 - https://github.com/typescript-eslint/typescript-eslint/tree/master/packages/parser#parseroptionsproject
 - https://github.com/angular-eslint/angular-eslint#migrating-from-codelyzer-and-tslint
 - typescript-eslint/typescript-eslint#2094

.eslintrc.js

@@ -0,0 +1,29 @@
+/**
+ * We are using the .JS version of an ESLint config file here so that we can
+ * add lots of comments to better explain and document the setup.
+ */
+module.exports = {
+  /**
+   * See packages/eslint-plugin/src/configs/README.md
+   * for what this recommended config contains.
+   */
+  extends: ['plugin:@angular-eslint/recommended'],
+  rules: {
+    // ORIGINAL tslint.json -> "directive-selector": [true, "attribute", "app", "camelCase"],
+    '@angular-eslint/directive-selector': [
+      'error',
+      { type: 'attribute', prefix: 'app', style: 'camelCase' },
+    ],
+
+    // ORIGINAL tslint.json -> "component-selector": [true, "element", "app", "kebab-case"],
+    '@angular-eslint/component-selector': [
+      'error',
+      { type: 'element', prefix: 'app', style: 'kebab-case' },
+    ],
+  },
+  parserOptions: {
+    ecmaVersion: 2020,
+    project: ['./tsconfig.app.json', './tsconfig.spec.json', './e2e/tsconfig.json'],
+    sourceType: "module",
+  },
+};

angular.json

@@ -98,8 +98,9 @@
           }
         },
         "lint": {
-          "builder": "@angular-devkit/build-angular:tslint",
+          "builder": "@angular-eslint/builder:lint",
           "options": {
+            "eslintConfig": ".eslintrc.js",
             "tsConfig": [
               "tsconfig.app.json",
               "tsconfig.spec.json",