docs(usage): one last usage example to typescript (#14481)

* docs(usage): setting angular usage example to be typescript

* docs(usage): one more javascript -> typescript

I forgot to save the last file…

core/src/components/toast/usage/angular.md

@@ -1,4 +1,4 @@
-```javascript
+```typescript
 import { Component } from '@angular/core';
 import { ToastController } from '@ionic/angular';