[examples][frameworks] Add missing examples and add a test to ensure every framework has an example (#4372)

* Add test to frameworks

* Add example for Docusaurus v2

* Add example for ionic-angular

* Update READMEs

* Use existing versions

* Reset yarn.lock

* Add schema validation and add missing Scully.io logo

examples/ionic-angular/src/test.ts

@@ -0,0 +1,20 @@
+// This file is required by karma.conf.js and loads recursively all the .spec and framework files
+
+import 'zone.js/dist/zone-testing';
+import { getTestBed } from '@angular/core/testing';
+import {
+  BrowserDynamicTestingModule,
+  platformBrowserDynamicTesting
+} from '@angular/platform-browser-dynamic/testing';
+
+declare const require: any;
+
+// First, initialize the Angular testing environment.
+getTestBed().initTestEnvironment(
+  BrowserDynamicTestingModule,
+  platformBrowserDynamicTesting()
+);
+// Then we find all the tests.
+const context = require.context('./', true, /\.spec\.ts$/);
+// And load the modules.
+context.keys().map(context);