Make the map.areas description list non-normative (same as HTML spec)

Author: Malvoz

spec/index.html

@@ -618,7 +618,8 @@ <h4>The <code>&lt;<dfn id="the-map-element">map</dfn>&gt;</code> element</h4>
  <p id="implementation">The <a href="#the-map-element"><code>map</code></a> element, in conjunction with child <a href="#the-layer-element"><code>layer</code></a> and optionally 
  <a href="#the-area-element"><code>area</code></a> elements, defines a map media element.</p>
 
- <dl class="def"><dt><var>map</var> . <a href="#dom-areas"><code>areas</code></a></dt>
+ <dl class="note" title="For web developers (non-normative)">
+ <dt><var>map</var>.<a href="#dom-areas"><code>areas</code></a></dt>
  <dd>
  <p>Returns an <a href="https://dom.spec.whatwg.org/#htmlcollection"><code>HTMLCollection</code></a> of the 
  <a href="#the-area-element"><code>area</code></a> elements in the