title: hide selection in ng-select
body: <p>We are using <a href="https://github.com/ng-select/ng-select" rel="nofollow noreferrer"><code>ng-select</code></a> in a project. And i need to provide functionality with dropdown, but my goal is to clear selection box after choose item from drop-down list. Anyone face this problem? </p>
  
  <pre><code> &lt;ng-select 
     #addmanager
     (change)="setLeagueAdmin($event)" 
     [items]="notAdminLeagueMembers"
     bindLabel="title"
     placeholder="Select from list"
     [clearSearchOnAdd]="true"
     [virtualScroll]="true"
     [clearable]="true"
     (scrollToEnd)="onAddManagerSscrollEnd()"&gt;
   &lt;/ng-select&gt;
  </code></pre>