Update README.

README

@@ -8,18 +8,35 @@ citizen and entreprise SSO.
 Installation
 ============
 
-- Install with `pip install authentic2-auth-fc`
-- Add `A2_FC_ENABLE = True` to your `local_settings.py` file
-- Define the needed parameters::
+Install with `pip install authentic2-auth-fc`
+
+Settings
+========
+
+Add `A2_FC_ENABLE = True` to your `local_settings.py` file
+Define the needed parameters::
 
    A2_FC_CLIENT_ID = 'id assigned by DISIC'
    A2_FC_CLIENT_SECRET = 'secret assigned by DISIC'
    A2_FC_VERIFY_CERTIFICATE = False # True for production
 
+A2_FC_CREATE = True set the plugin in provisionning mode. If a sub is unknown,
+a user is created instead of asking authentication.
+
+When the create mode is enabled, the link for unlinking is hidden on the
+profile frontend. This is due to the not yet implemented need of asking
+the user credentiels when unlinking a user created without any other credential
+that the authentication delegation. Unlinking meaning, loosing access to this
+account at the end of the current session. To enable unlinking when create is
+unabled use A2_FC_ENABLE_UNLINK_WHEN_CREATE = True.
+
+A2_FC_LOGOUT_WHEN_UNLINK = True is using to trigger a logout toward the OP
+after unlinking.
+
 Platforms
 =========
 
-When testing against another platform of France Connect you must change
+When testing against another platform than FranceConnect you must change
 the default endpoints URL in your `local_settings.py` file::
 
    A2_FC_AUTHORIZE_URL = 'https://fcp.integ01.dev-franceconnect.fr/api/v1/authorize'
@@ -30,13 +47,29 @@ the default endpoints URL in your `local_settings.py` file::
 Data Providers
 ==============
 
-You can define data provider endpoints with the following dictionnary structure :
+You can define data provider endpoints with the following dictionnary :
 
 A2_FC_FD_LIST = {
     'revenu_fiscal_de_reference': [
         {
+            'name': 'OpenDataSoft',
             'url': 'https://datafranceconnect.opendatasoft.com/api/records/1.0/search',
             'query_dic': {'dataset': 'guichet-des-bretons', },
         },
     ],
 }
+
+Data is requested using the login or link endpoint view giving space delimited
+scopes in the `fd_scopes` get parameter :
+
+    fc/callback/?next=%2F&fd_scopes=revenu_fiscal_de_reference scolarite
+
+The data received is recorded in the session with a dictionnary named `fc-data`
+with scopes as keys and lists of data as values. A data is a tuple
+FD name and data content.
+
+fc_data_dic = {
+    scope_name = [
+        [FD_name, data],
+    ],
+}