feat: upgrade to Angular v21 RC0 (#24)

Author: brandonroberts

README.md

@@ -24,6 +24,12 @@ npm run storybook
 npm run build-storybook
 ```
 
+## Test
+
+```sh
+npm run test-storybook
+```
+
 ## Support
 
 You can support this work by [sponsoring me on GitHub](https://github.com/sponsors/brandonroberts).

angular.json

@@ -16,9 +16,6 @@
             "outputPath": "dist/angular-v17-vite-storybook",
             "index": "src/index.html",
             "browser": "src/main.ts",
-            "polyfills": [
-              "zone.js"
-            ],
             "tsConfig": "tsconfig.app.json",
             "assets": [
               "src/favicon.ico",