docs: Add initial documentation

docs/API/index.rst

@@ -0,0 +1,30 @@
+*****************
+API Documentation
+*****************
+
+The Notfellchen API serves the purpose of supporting 3rd-person applications and anything you can think of basically.
+
+.. warning::
+    The current API is limited in it's functionality. I you miss a specific feature please contact the developer!
+
+API Access
+==========
+
+Via browser
+-----------
+
+When a user is logged in, they can easily access the API in their browser, authenticated by their session.
+The API endpoint can be found at /library/api/
+http://notfellchen.org/
+
+Via token
+---------
+
+.. warning::
+    This is currently not supported.
+
+All users are able to generate a token that allows them to use the API. This can be done in the user's profile.
+An application can then send this token in the request header for authorization.
+
+.. code-block::
+    $ curl -X GET http://notfellchen.org/api/adoption_notice -H 'Authorization: Token 49b39856955dc6e5cc04365498d4ad30ea3aed78'