title: 'ng-select' is not a known element
body: <p>this is my code:
  I want to add on my form <a href="https://github.com/ng-select/ng-select" rel="noreferrer">https://github.com/ng-select/ng-select</a> multi select for tags input.</p>
  
  <p>components.module.ts:</p>
  
  <pre><code>import { NgModule } from '@angular/core';
  import { CommonModule } from '@angular/common';
  import { HttpClientModule } from '@angular/common/http';
  
  import { FormsModule, ReactiveFormsModule } from '@angular/forms';
  import { NgSelectModule } from '@ng-select/ng-select';
  
  
  @NgModule({
    imports: [
      CommonModule,
      HttpClientModule,
      FormsModule,
      ReactiveFormsModule,
      NgSelectModule,
     ]
  
  })
  
  export class ComponentsModule { }
  </code></pre>
  
  <p>my modaltest.component.html</p>
  
  <pre><code>  &lt;div class="col-xs-12 col-sm-12 col-md-12 col-lg-12"&gt;
                      &lt;label class="control-label"&gt;
                          &lt;strong&gt;Gusti:&lt;/strong&gt;
                      &lt;/label&gt;
                 [ERROR] ---&gt;             &lt;ng-select [items]="testitems" [hideSelected]="true" multiple="true" bindLabel="text1"&gt;&lt;/ng-select&gt; 
     &lt;/div&gt;
  </code></pre>
  
  <p>My error is: Can't bind to 'items' since it isn't a known property of 'ng-select' Why????? </p>
  
  <p>Can you help me?
  Thank's a lot! </p>