docs(afs): Fix the stackblitz link on the querying example (#1182)

Author: jamesdaniels

docs/firestore/querying-collections.md

@@ -77,7 +77,7 @@ size$.next('small');
 
 **Example app:**
 
-[See this example in action on StackBlitz](https://stackblitz.com/edit/angularfire-db-api-bimovw).
+[See this example in action on StackBlitz](https://stackblitz.com/edit/angularfire-db-api-fbad9p).
 
 ```ts
 import { Component } from '@angular/core';
@@ -170,4 +170,4 @@ export class AppComponent {
 }
  ```
 
-### [Next Step: Getting started with Firebase Authentication](../auth/getting-started.md)
+### [Next Step: Getting started with Firebase Authentication](../auth/getting-started.md)