cli: add and use app:lint + include default eslint config in cli

packages/app/.eslintrc.js

@@ -1,28 +0,0 @@
-module.exports = {
-  parser: '@typescript-eslint/parser', // Specifies the ESLint parser
-  extends: [
-    // Extend on the config used in `react-scripts`
-    require.resolve('react-scripts/node_modules/eslint-config-react-app'),
-    // If you want extra rules/extensions, it can be added here:
-    // 'plugin:react/recommended', // Uses the recommended rules from @eslint-plugin-react
-    // 'plugin:@typescript-eslint/recommended', // Uses the recommended rules from @typescript-eslint/eslint-plugin
-  ],
-  parserOptions: {
-    ecmaVersion: 2018, // Allows for the parsing of modern ECMAScript features
-    sourceType: 'module', // Allows for the use of imports
-    ecmaFeatures: {
-      jsx: true, // Allows for the parsing of JSX
-    },
-  },
-  rules: {
-    // Place to specify ESLint rules. Can be used to overwrite rules specified from the extended configs
-    // e.g. "@typescript-eslint/explicit-function-return-type": "off",
-  },
-  settings: {
-    react: {
-      version: 'detect', // Tells eslint-plugin-react to automatically detect the version of React to use
-    },
-  },
-  // Adding this to .eslintignore just doesn't even, let me know if you can make it work ._.
-  ignorePatterns: ['**/*_pb.js', '**/*_pb.d.ts'],
-};

packages/app/package.json

@@ -28,10 +28,7 @@
     "start": "cross-env EXTEND_ESLINT=true SKIP_PREFLIGHT_CHECK=true backstage-cli watch-deps -- react-scripts start",
     "build": "cross-env EXTEND_ESLINT=true SKIP_PREFLIGHT_CHECK=true react-scripts build",
     "test": "cross-env EXTEND_ESLINT=true SKIP_PREFLIGHT_CHECK=true react-scripts test",
-    "lint": "cross-env EXTEND_ESLINT=true eslint ./src/**/*.{ts,tsx} --max-warnings=0 --format=codeframe"
-  },
-  "eslintConfig": {
-    "extends": "react-app"
+    "lint": "backstage-cli app:lint"
   },
   "browserslist": {
     "production": [