Add mention for HTTP API explorer in relevant places.

docs/api/http.rst

@@ -10,7 +10,9 @@ HTTP JSON-RPC API
 The :ref:`ext-http` extension makes Mopidy's :ref:`core-api` available using
 JSON-RPC over HTTP using HTTP POST and WebSockets. We also provide a JavaScript
 wrapper, called :ref:`Mopidy.js <mopidy-js>`, around the JSON-RPC over
-WebSocket API for use both from browsers and Node.js.
+WebSocket API for use both from browsers and Node.js. The
+:ref:`http-explore-extension` extension, can also be used to get you
+familiarized with HTTP based APIs.
 
 .. warning:: API stability
 

docs/ext/api_explorer.rst

@@ -0,0 +1,12 @@
+.. _http-explore-extension:
+
+Mopidy-API-Explorer
+===================
+
+https://github.com/dz0ny/mopidy-api-explorer
+
+Web extension for browsing the Mopidy HTTP API.
+
+.. image:: /ext/api_explorer.png
+    :width: 1176
+    :height: 713

docs/ext/web.rst

@@ -12,12 +12,7 @@ This list is moderated and updated on a regular basis. If you want your package
 to show up here, follow the :ref:`guide on creating extensions <extensiondev>`.
 
 
-Mopidy-API-Explorer
-===================
-
-https://github.com/dz0ny/mopidy-api-explorer
-
-Web extension for browsing the Mopidy HTTP API.
+.. include:: /ext/api_explorer.rst
 
 
 .. include:: /ext/lux.rst

docs/extensiondev.rst

@@ -418,7 +418,8 @@ Example web application
 
 As of Mopidy 0.19, extensions can use Mopidy's builtin web server to host
 static web clients as well as Tornado and WSGI web applications. For several
-examples, see the :ref:`http-server-api` docs.
+examples, see the :ref:`http-server-api` docs or explore with
+:ref:`http-explore-extension` extension.
 
 
 Example GStreamer element