build(aio): move doc-gen stuff from angular.io (#14097)

tools/docs/angular.io-package/mocks/testSrc.ts

@@ -0,0 +1,42 @@
+/**
+ * @license
+ * Copyright Google Inc. All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+
+/**
+ * @module
+ * @description
+ * This is the module description
+ */
+
+export * from './importedSrc';
+
+/**
+ * This is some random other comment
+ */
+
+/**
+ * This is MyClass
+ */
+export class MyClass {
+  message: String;
+
+  /**
+   * Create a new MyClass
+   * @param {String} name The name to say hello to
+   */
+  constructor(name) { this.message = 'hello ' + name; }
+
+  /**
+   * Return a greeting message
+   */
+  greet() { return this.message; }
+}
+
+/**
+ * An exported function
+ */
+export const myFn = (val: number) => val * 2;