update readme

http-api/app/rules/enrollment.py

@@ -41,6 +41,9 @@ class LifecycleEvents(str, Enum):
     # Archive the course after the certificate expires
     COURSE_ARCHIVED = 'schedules#course_archived'
 
+    # When the access period ends for a course without a certificate
+    COURSE_EXPIRED = 'schedules#course_expired'
+
 
 def enroll(
     enrollment: Enrollment,
@@ -95,6 +98,18 @@ def enroll(
         },
     )
 
+    transact.put(
+        item={
+            'id': enrollment.id,
+            'sk': LifecycleEvents.COURSE_EXPIRED,
+            'name': user.name,
+            'email': user.email,
+            'course': course.name,
+            'create_date': now_,
+            'ttl': ttl(start_dt=now_ + timedelta(days=course.access_period)),
+        },
+    )
+
     return persistence_layer.transact_write_items(transact)