feat: Supply documentation links for course apps from the backend (#28327)

Instead of hard-coding the "Learn More" and potentially other links for course
apps in the course authoring  MFEs this change loads those URLs from the
django settings as part of each individual course app.

lms/djangoapps/courseware/plugins.py

@@ -25,6 +25,9 @@ class ProgressCourseApp(CourseApp):
     app_id = "progress"
     name = _("Progress")
     description = _("Keep learners engaged and on track throughout the course.")
+    documentation_links = {
+        "learn_more_configuration": settings.PROGRESS_HELP_URL,
+    }
 
     @classmethod
     def is_available(cls, course_key: CourseKey) -> bool:
@@ -69,6 +72,9 @@ class TextbooksCourseApp(CourseApp):
     app_id = "textbooks"
     name = _("Textbooks")
     description = _("Create and manage a library of course readings, textbooks, and chapters.")
+    documentation_links = {
+        "learn_more_configuration": settings.TEXTBOOKS_HELP_URL,
+    }
 
     @classmethod
     def is_available(cls, course_key: CourseKey) -> bool:  # pylint: disable=unused-argument
@@ -117,6 +123,9 @@ class CalculatorCourseApp(CourseApp):
     app_id = "calculator"
     name = _("Calculator")
     description = _("Provide an in-course calculator for simple and complex calculations.")
+    documentation_links = {
+        "learn_more_configuration": settings.CALCULATOR_HELP_URL,
+    }
 
     @classmethod
     def is_available(cls, course_key: CourseKey) -> bool: