Docs updates for amp-position-observer launch (#11260)

* Docs updates for amp-position-observer launch

* review comments

examples/amp-position-observer.amp.html

@@ -94,10 +94,6 @@
     </script>
   </amp-animation>
   <main>
-    <h1>amp-position-observer (Experimental)</h1>
-    <h1><div>Please ensure <pre>amp-position-observer</pre> experiment flag is enabled first</h1> Running
-      <pre>AMP.toggleExperiment('amp-position-observer', true);</pre> in Developer Console will enable the experiment for your browser.
-    </div>
     <div class="spacer"></div>
 
     <h2>Scrollbound animations with amp-position-observer and amp-animation</h2>

extensions/amp-position-observer/amp-position-observer.md

@@ -24,10 +24,6 @@ limitations under the License.
     other components such as <code>&lt;amp-animation></code>
     </td>
   </tr>
-  <tr>
-    <td width="40%"><strong>Availability</strong></td>
-    <td><a href="https://www.ampproject.org/docs/reference/experimental.html">Experimental</a></td>
-  </tr>
   <tr>
     <td width="40%"><strong>Required Script</strong></td>
     <td><code>&lt;script async custom-element="amp-position-observer" src="https://cdn.ampproject.org/v0/amp-position-observer-0.1.js">&lt;/script></code></td>
@@ -38,7 +34,10 @@ limitations under the License.
   </tr>
   <tr>
     <td width="40%"><strong>Examples</strong></td>
-    <td><a href="https://github.com/ampproject/amphtml/blob/master/examples/amp-position-observer.amp.html">amp-position-observer</a></td>
+    <td>
+      <a href="https://github.com/ampproject/amphtml/blob/master/examples/amp-position-observer.amp.html">amp-position-observer</a><br>
+      <a href="https://codepen.io/collection/nMJYrv/">CodePen collection with 6 samples</a>
+    </td>
   </tr>
 </table>