Update setup.mdx (#5287)

* Update setup.mdx

Hi -

Update made for Angular 15 support.  src/polyfill.ts does not exist.  Aligning this documentation with Amplify docs - https://ui.docs.amplify.aws/angular/getting-started/troubleshooting.

Regards,
Rennay

* Update using BlockSwitcher 

Hi -

As per suggestion from @tannerabread, I have made the update using BlockSwitcher.  Apologies in advance if not completed correctly.  I could not confirm using Preview.  Please let me know if any further update required.  Again, aligning to https://ui.docs.amplify.aws/angular/getting-started/troubleshooting.

Regards,
Rennay

Author: rennay

src/fragments/start/getting-started/angular/setup.mdx

@@ -9,16 +9,56 @@ npx -p @angular/cli ng new amplify-app
 cd amplify-app
 ```
 
-### Angular 6+ Support
+Angular 6+ does not include shims for 'global' or 'process'.
 
-Angular 6+ does not include shims for 'global' or 'process' as provided in previous versions. Add the following to your `src/polyfills.ts` file to recreate them: 
+<BlockSwitcher>
+
+<Block name="Angular 15">
+
+First, create `src/polyfills.ts` and add the following:
 
 ```javascript
 (window as any).global = window;
 (window as any).process = {
   env: { DEBUG: undefined },
 };
-``` 
+```
+
+Then, open your `angular.json` file, and add `src/polyfills.ts` to polyfills array(s) in your `angular.json`. These arrays are located in projects.`<project-name>.architect.<task-name>.options`.
+
+```javascript
+"polyfills": [
+  "zone.js",
+  "src/polyfills.ts"
+],
+```
+
+And finally, make sure to add `src/polyfills` to files in your `tsconfig.app.json`:
+
+```javascript
+{
+  "files": [
+    "src/main.ts",
+    "src/polyfills.ts"
+  ],
+}
+```
+</Block>
+
+<Block name="Angular 6-14">
+
+Add the following to your `src/polyfills.ts` file to recreate them: 
+
+```javascript
+(window as any).global = window;
+(window as any).process = {
+  env: { DEBUG: undefined },
+};
+```
+
+</Block>
+
+</BlockSwitcher>
 
 ## Create a new Amplify backend