docs: include interpolations in the "What is Angular" example (#42702)

Affected URL - https://angular.io/guide/what-is-angular#template

Fixes #42665

PR Close #42702

aio/content/examples/what-is-angular/e2e/src/app.e2e-spec.ts

@@ -6,11 +6,11 @@ describe('What is Angular', () => {
   const paragraphs = element.all(by.css('p'));
   const buttons = element.all(by.css('button'));
   const templateButton = buttons.get(1);
-  const templateText = paragraphs.get(3);
+  const templateText = paragraphs.get(4);
   const messageButton = buttons.get(0);
   const messageText = paragraphs.get(2);
   const ngIfButton = buttons.get(2);
-  const ngIfText = paragraphs.get(4);
+  const ngIfText = paragraphs.get(5);
   const diButton = buttons.get(3);
 
   beforeEach(() => browser.get(''));

aio/content/examples/what-is-angular/src/app/hello-world-bindings/hello-world-bindings.component.html

@@ -4,3 +4,4 @@
 <!-- #docregion bindings -->
 <p [id]="sayHelloId" [style.color]="fontColor">You can set my color in the component!</p>
 <!-- #enddocregion -->
+<p>My color is {{ fontColor }}</p>

aio/content/guide/what-is-angular.md

@@ -82,7 +82,7 @@ The preceding example calls a method, which is defined in the component class:
 
 <code-example path="what-is-angular/src/app/hello-world-bindings/hello-world-bindings.component.ts" region="method"></code-example>
 
-The following is an example of interpolation and bindings within an Angular template:
+The following is a combined example of Interpolation, Property Binding and Event Binding within an Angular template:
 
 <code-tabs linenums="true">
   <code-pane