Some changes to configuration and example element

src/my-element.ts

@@ -0,0 +1,38 @@
+import { LitElement, html, customElement, property, css } from 'lit-element';
+
+@customElement('my-element')
+class MyElement extends LitElement {
+
+  static styles = css`
+    :host {
+      display: block;
+      border: solid 1px gray;
+      padding: 16px;
+      max-width: 800px;
+    }
+  `;
+
+  @property()
+  name = 'World';
+
+  @property({type: Number})
+  count = 0;
+
+  render(){
+    return html`
+      <h1>Hello, ${this.name}!</h1>
+      <button @click=${this._onClick}>Click Count: ${this.count}</button>
+      <div class="slot"><slot></slot></div>
+    `;
+  }
+
+  private _onClick() {
+    this.count++;
+  }
+}
+
+declare global {
+  interface HTMLElementTagNameMap {
+    'my-element': MyElement;
+  }
+}