title: Cannot find @angular/fire/firestore module error in VScode
body: <p>I am very new to firebase firestore. 
  And this is my first project with firestore.
  I installed angular fire with this command </p>
  
  <pre><code>npm install firebase @angular/fire --save
  </code></pre>
  
  <p>and now importing the angularfiremodule like this </p>
  
  <pre><code>import { AngularFireModule } from '@angular/fire';
  </code></pre>
  
  <p>and angularfirestoremodule like this</p>
  
  <pre><code>import { AngularFirestoreModule } from '@angular/fire/firestore';
  </code></pre>
  
  <p>But this is giving me error </p>
  
  <blockquote>
    <p>Cannot find module '@angular/fire'.ts(2307)</p>
  </blockquote>
  
  <p>Any idea what might be the error?
  I tried google searching but since I am new to firebase, everything seems very mixed up to me. 
  Also, I'm using ionic version 4, Angular version 8.1.3 and node version 10.16.3 if that makes any difference.</p>
  
  <p>Angularfire2 was working fine previously, but since it's deprecated, I want to move to angular/fire.</p>