Update install-and-setup.md (#3500)

Replaced missing semicolon in Step 4 code block

Author: erikhaddad

docs/install-and-setup.md

@@ -73,7 +73,7 @@ import { Observable } from 'rxjs';
   styleUrls: ['app.component.css']
 })
 export class AppComponent {
-  firestore: Firestore = inject(Firestore)
+  firestore: Firestore = inject(Firestore);
   items$: Observable<any[]>;
 
   constructor() {