addressed comments

Author: tinayuangao

src/demo-app/a11y/icon/icon-a11y.html

@@ -1,17 +1,29 @@
 <section>
-  <h2>Fingerprint icon (Decorative icons)</h2>
+  <h2>Fingerprint status</h2>
+  <p>Showing a status message with a purely decorative icon</p>
   <md-icon color="primary">fingerprint</md-icon>
+  Your fingerprint was recorded!
 </section>
 
 <section>
-  <h2>Delete icon (Interactive icons) </h2>
+  <h2>Delete icon button </h2>
+  <p>Showing a button with interactive icon which can perform an action</p>
   <button md-icon-button aria-label="Delete" (click)="deleteIcon()">
     <md-icon color="accent">delete</md-icon>
   </button>
 </section>
 
 <section>
-  <h2>Done icon (Indicator icons) </h2>
+  <h2>Home link </h2>
+  <p>Showing a link with interactive icon</p>
+  <a md-icon-button aria-label="Home" href="http://www.google.com">
+    <md-icon color="primary">home</md-icon>
+  </a>
+</section>
+
+<section>
+  <h2>Done status </h2>
+  <p>Showing a status indicator with an indicator icon</p>
   <md-icon color="warn">done</md-icon>
   <span class="cdk-visually-hidden">Done</span>
 </section>