add geolocation search for public channels

app/views/docs/channels/_index.html.erb

@@ -16,6 +16,14 @@ Valid parameters:
   <li><b>username</b> (string) Person's username that you want to search Channels for (optional)</li>
 </ul>
 
+<br>
+You can also search for Channels within a certain distance of a location by including the following location parameters:
+<ul>
+  <li><b>latitude</b> (decimal) - Latitude of location in degrees. (optional)</li>
+  <li><b>longitude</b> (decimal) - Longitude of location in degrees. (optional)</li>
+  <li><b>distance</b> (decimal) - Distance in kilometers from location. (optional)</li>
+</ul>
+
 <br>
 Example GET:
 
@@ -163,6 +171,7 @@ Valid parameters:
   <li><b>api_key</b> (string) - Your Account API Key (this is different from a Channel API Key, and can be found in your Account settings). (required)</li>
 </ul>
 
+
 <br>
 Example GET: