change documentation of html-custom-element.js

src/html-custom-element.js

@@ -5,22 +5,21 @@
  * @license MIT
  */
 
-/**
- * Class extending the native HTMLElement. To reduce redundant code it
- * provides methods often used while creating custom elements. If
- * possible your own custom elements should inherit from this class.
- */
-
 export class HTMLCustomElement extends HTMLElement {
 
+  /**
+   * This interface class extends the native `HTMLElement` interface and
+   * provides some additional, often used methods.
+   */
   constructor() {
     super();
     this._observers = [];
   }
 
   /**
-   * This method is an extension of the nativ getElementById() JS
-   * function but works asynchroneous.
+   * equivalent of native getElementById, but works asynchroneous and
+   * returns a Promise which resolves when the requested element is
+   * aviable.
    *
    * @param {string} id - id of DOM element waiting for
    * @return {Promise<Node>} - A Promise to the requested Element
@@ -40,9 +39,9 @@ export class HTMLCustomElement extends HTMLElement {
   }
 
   /**
-   * This method offers an easy way to bind a mutationObserver to an
-   * element. Every time an attribute of Node changes, function fn
-   * gets called.
+   * Like an event listener but for attributes. It observes an
+   * elements attribute for changes and invokes a pre defined callback
+   * function. For this native js MutationObservers are used.
    *
    * @param {HTMLNode} Node - reference to the HTML Node
    * @param {string} Attr - attribute name to observe