Add text input for answers

src/app/content-creation/content-creation.component.html

 <mat-form-field>
-  <input matInput placeholder="Input">
+  <input matInput placeholder="Topic">
 </mat-form-field>
 
 <p></p>
 
 <mat-form-field>
-  <textarea matInput placeholder="Textarea"></textarea>
+  <textarea matInput placeholder="Text"></textarea>
 </mat-form-field>
 
 <p></p>
 
 <mat-radio-group>
-  <mat-radio-button value="1">Answer 1</mat-radio-button>
+  <mat-radio-button value="1"><input matInput placeholder="Answer 1"></mat-radio-button>
   <p></p>
-  <mat-radio-button value="2">Answer 2</mat-radio-button>
+  <mat-radio-button value="1"><input matInput placeholder="Answer 2"></mat-radio-button>
   <p></p>
-  <mat-radio-button value="1">Answer 3</mat-radio-button>
+  <mat-radio-button value="1"><input matInput placeholder="Answer 3"></mat-radio-button>
   <p></p>
-  <mat-radio-button value="2">Answer 4</mat-radio-button>
+  <mat-radio-button value="1"><input matInput placeholder="Answer 4"></mat-radio-button>
 </mat-radio-group>