refactor: added slugs to course and topics to make nice urls

- the slug is autogenerated from the title
- the slug of a topic is unique among all the topics of that course

community/www/courses/index.py

@@ -7,6 +7,6 @@ def get_context(context):
 def get_courses():
     courses = frappe.get_all(
         "LMS Course",
-        fields=['name', 'title', 'description']
+        fields=['name', 'slug', 'title', 'description']
     )
     return courses