[enh] add morty documentation

docs/admin/morty.rst

@@ -0,0 +1,21 @@
+How to setup result proxy
+=========================
+
+By default searx can only act as an image proxy for result images,
+but it is possible to proxify all the result URLs with an external service,
+`morty <https://github.com/asciimoo/morty>`__.
+
+To use this feature, morty has to be installed and activated in searx's ``settings.yml``.
+
+Add the following snippet to your ``settings.yml`` and restart searx:
+
+
+.. code:: yaml
+
+    result_proxy:
+        url : http://127.0.0.1:3000/
+        key : your_morty_proxy_key
+
+``url`` is the address of the running morty service
+
+``key`` is an optional argument, see `morty's README <https://github.com/asciimoo/morty>`__ for more information.

docs/index.rst

@@ -40,6 +40,7 @@ Administrator documentation
    dev/install/installation
    admin/api
    admin/filtron
+   admin/morty
 
 Developer documentation
 -----------------------