title: Relative references must start with either "/", "./", or "../"
body: <p>I am newbie to lit-element, and when use import to include the library, I am getting error as: </p>
  
  <blockquote>
    <p>Uncaught TypeError: Failed to resolve module specifier "lit-element".
    Relative references must start with either "/", "./", or "../".</p>
  </blockquote>
  
  <p>Please provide any alternatives/solutions.</p>
  
  <pre><code>import { LitElement, html } from 'lit-element';
  
  class MyElement extends LitElement {
    render(){
      return html`
        &lt;div&gt;
          &lt;p&gt;A paragraph&lt;/p&gt;
        &lt;/div&gt;
      `;
    }
  }
  customElements.define('my-element', MyElement);
  
  </code></pre>