title: fullcalendar lib before attempting to import a plugin
body: <p>I installed FullCalendar 5 in my Angular 9 project</p>
  <p>then I get this error in the console of browser and anything appears in the page</p>
  <pre><code>vdom.js:3 Uncaught Error: Please import the top-level full calendar lib before attempting to import a plugin.
      at Module../node_modules/@fullcalendar/common/vdom.js (vdom.js:3)
      at __webpack_require__ (bootstrap:79)
      at Module../node_modules/@fullcalendar/common/main.js (main.js:1)
      at __webpack_require__ (bootstrap:79)
      at Module../node_modules/@fullcalendar/daygrid/main.js (main.js:1)
      at __webpack_require__ (bootstrap:79)
      at Module../src/app/demo/demo.component.ts (demo.component.ts:1)
      at __webpack_require__ (bootstrap:79)
      at Module../src/app/Modules/app-routing.module.ts (app-routing.module.ts:1)
      at __webpack_require__ (bootstrap:79)
  </code></pre>
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-js lang-js prettyprint-override"><code>import { BrowserModule } from '@angular/platform-browser';
  import { NgModule } from '@angular/core';
  import { FullCalendarModule } from '@fullcalendar/angular'; // for FullCalendar!
  import { AppComponent } from './app.component';
  
  @NgModule({
    declarations: [
      AppComponent
    ],
    imports: [
      BrowserModule,
      FullCalendarModule // for FullCalendar!
    ],
    providers: [],
    bootstrap: [AppComponent]
  })
  export class AppModule { }</code></pre>
  </div>
  </div>
  </p>
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-js lang-js prettyprint-override"><code>import { Component } from '@angular/core';
  import dayGridPlugin from '@fullcalendar/daygrid';
  
  @Component({
    selector: 'app-root',
    templateUrl: './app.component.html',
    styleUrls: ['./app.component.scss']
  })
  export class AppComponent {
  
    calendarOptions = {
      plugins: [dayGridPlugin],
      initialView: 'dayGridMonth'
    };
  
  }</code></pre>
  </div>
  </div>
  </p>
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;full-calendar [options]="calendarOptions"&gt;&lt;/full-calendar&gt;</code></pre>
  </div>
  </div>
  </p>