Throttling documentation added

Author: vsevolod-kolchinsky

docs/configuration.rst

@@ -49,3 +49,20 @@ Configuration
 - **OLD_PASSWORD_FIELD_ENABLED** - set it to True if you want to have old password verification on password change enpoint (default: False)
 
 - **LOGOUT_ON_PASSWORD_CHANGE** - set to False if you want to keep the current user logged in after a password change
+
+
+Throttling
+=============
+
+You may specify custom throttling for ``rest_auth.register.views.RegisterView`` by specifying DRF settings:
+
+    .. code-block:: python
+
+        REST_FRAMEWORK = {
+            'DEFAULT_THROTTLE_RATES': {
+                'anon': '6/m',
+                'register_view':'1/h',
+            },
+        }
+    
+