Document new router settings

Author: dimitri-justeau

docs/settings.md

@@ -6,7 +6,12 @@ source_filename: settings
 To set DRF docs' settings just include the dictionary below in Django's `settings.py` file.
 
     REST_FRAMEWORK_DOCS = {
-        'HIDE_DOCS': True
+        'HIDE_DOCS': True,
+        'MODULE_ROUTERS': {
+            'project.accounts.urls': 'accounts_router',
+        },
+        'DEFAULT_MODULE_ROUTER': 'router',
+        'DEFAULT_ROUTER': 'project.urls.default_router',
     }
 
 
@@ -21,9 +26,29 @@ You can use hidden to prevent your docs from showing up in different environment
 
 Then set the value of the environment variable `HIDE_DRFDOCS` for each environment (ie. Use `.env` files)
 
+##### MODULE_ROUTERS
+Use this setting to manually bind url modules to a router instance. The router must be defined in the module, or imported in the module.
+For instance, if the router of an app called 'gifts' is 'gifts_router', and the router of another app called 'scuba_diving' is 'scuba_diving_router', the MODULE_ROUTERS setting should look like:
+
+    'MODULE_ROUTERS': {
+        'gifts.urls': 'gift_router',
+        'scuba_diving.urls': 'scuba_diving_router'
+    }
+
+If there is no entry for a given module, if this setting is not set, or if it is set to None, the value of the DEFAULT_MODULE_ROUTER setting is used. 
+
+##### DEFAULT_MODULE_ROUTER
+When set, the value of this setting will be used to find a router for a urls module. If there is no router having the DEFAULT_MODULE_ROUTER name, the setting is ignored and the value of DEFAULT_ROUTER is used.
+
+##### DEFAULT_ROUTER
+When defined, this setting must describe a python dotted path leading to the router that should be used when MODULE_ROUTERS and DEFAULT_MODULE_ROUTER are not set.
+This parameter is useful when there is only one router for your whole API.
+
 ### List of Settings
 
-| Setting | Type    | Options         | Default |
-|---------|---------|-----------------|---------|
-|HIDE_DOCS| Boolean | `True`, `False` | `False` |
-|         |         |                 |         |
+| Setting             | Type                                                      | Options         | Default |
+|---------------------|-----------------------------------------------------------|-----------------|---------|
+|HIDE_DOCS            | Boolean                                                   | `True`, `False` | `False` |
+|MODULE_ROUTERS       | dict of python dotted paths -> router instance name       |                 | `None`  |
+|DEFAULT_MODULE_ROUTER| str representing a default router instance name           |                 | `None`  |
+|DEFAULT_ROUTER       | str representing a python dotted path to a router instance|                 | `None`  |