Adding a quick hint to the API in the documentation.

docs/api.rst

@@ -0,0 +1,16 @@
+API
+===
+
+**django-admin2** comes with a builtin REST-API for accessing all the
+resources you can get from the frontend via JSON.
+
+The API can be found at the URL you choose for the admin2 and then append
+``api/v0/``.
+
+If the API has changed in a backwards-incompatible way we will increase the
+API version to the next number. So you can be sure that you're frontend code
+should keep working even between updates to more recent django-admin2
+versions.
+
+However currently we are still in heavy development, so we are using ``v0``
+for the API, which means is subject to change and being broken at any time.

docs/index.rst

@@ -61,6 +61,7 @@ Content
    :maxdepth: 2
 
    contributing
+   api
    design
    meta
 
@@ -71,4 +72,3 @@ Indices and tables
 * :ref:`genindex`
 * :ref:`modindex`
 * :ref:`search`
-