title: fixed item in mat-menu angular
body: <p>I have this code snippet to show unread notification to user:</p>
  <pre><code>&lt;mat-menu #menu=&quot;matMenu&quot;&gt;
      &lt;div class=&quot;menu-item&quot; mat-menu-item *ngFor=&quot;let item of notifications&quot;&gt;
          ...item content
      &lt;/div&gt;
      &lt;button class=&quot;show-all-btn&quot; mat-menu-item (click)=&quot;navigateToNotification()&quot;&gt;show all&lt;/button&gt;
  &lt;/mat-menu&gt;
  </code></pre>
  <p>as you can see in the above code I generate menu item by *ngFor directive and as last menu item I add &quot;show all&quot; button that every time exist in my menu.
  How can I show this button at the bottom of mat-menu in fixed position which can't move by scrolling items</p>