fix: use correct heading levels (#541)

Author: arjunpras

apps/timestamp-microservice/views/index.html

@@ -20,13 +20,13 @@
     <h1>Timestamp Microservice</h1>
     <hr />
     <div class="container">
-      <h3>Example Usage:</h3>
+      <h2>Example Usage:</h2>
       <ul>
         <li><a href="api/2015-12-25">[project url]/api/2015-12-25</a></li>
         <li><a href="api/1451001600000">[project url]/api/1451001600000</a></li>
       </ul>
 
-      <h3>Example Output:</h3>
+      <h2>Example Output:</h2>
       <p>
         <code
           >{"unix":1451001600000, "utc":"Fri, 25 Dec 2015 00:00:00 GMT"}</code