Merge pull request SharePoint#8025 from rob-windsor/rw-spfx114-build-first-ext-part-2

Update Use page placeholders from Application Customizer (Hello World part 2) for SPFx 1.14

Author: andrewconnell

docs/images/ext-app-header-footer-visible.png

@@ -1,7 +1,7 @@
 ---
 title: Use page placeholders from Application Customizer (Hello World part 2)
 description: Extend your Hello World extension to take advantage of page placeholders by using SharePoint Framework (SPFx) Extensions.
-ms.date: 06/22/2020
+ms.date: 06/07/2022
 ms.prod: sharepoint
 ms.custom: scenarios:getting-started
 ---
@@ -139,15 +139,14 @@ Notice that you're requesting a well-known placeholder by using the correspondin
 8. Update the `onInit()` method code as follows:
 
     ```typescript
-    @override
     public onInit(): Promise<void> {
       Log.info(LOG_SOURCE, `Initialized ${strings.Title}`);
 
       // Wait for the placeholders to be created (or handle them being changed) and then
       // render.
       this.context.placeholderProvider.changedEvent.add(this, this._renderPlaceHolders);
 
-      return Promise.resolve<void>();
+      return Promise.resolve();
     }
     ```