[Docs] Add info about activity endpoints

README.md

@@ -30,6 +30,23 @@ urlpatterns = [
 ```
 
 ## Activity streams
-
-Accepted actions:
-- user accessed the platform
+Its possible to log `user-access` by sending a POST request to `/api/stats/user-access/`. Payload example:
+```json
+{
+  "area": "dashboard"
+}
+```
+Note: available areas must be created via Django Admin previously: `<HOST>/django/admin/stats/accessiblearea/`
+
+
+To log generic activities, send a POST request to `/api/user-actions/`.
+```json
+{
+  "verb": "created comment",
+  "action_object_id": 7,         # optional
+  "action_object_type": "Topic", # optional
+  "target_id": 26,               # optional
+  "target_type": "Forum"         # optional
+}
+```
+Note: any model used as object or target must have been previously registered at `django-courses/courses/stats/apps.py`