🩹(schema): add course query param to product retrieve route

course is a mandatory query param for product.retrieve.
we need it in order to correctly generate javascript api client.

CHANGELOG.md

@@ -15,6 +15,7 @@ and this project adheres to
 ## Added
 
 - Add yarn cli to generate joanie api client in TypeScript
+- Add course query param to openapi schema on route products.retrieve
 
 ### Removed
 

src/backend/joanie/core/api.py

@@ -6,6 +6,8 @@
 from django.http import HttpResponse
 from django.utils.translation import gettext_lazy as _
 
+from drf_yasg import openapi
+from drf_yasg.utils import swagger_auto_schema
 from rest_framework import mixins, pagination, permissions, viewsets
 from rest_framework.decorators import action
 from rest_framework.exceptions import ValidationError as DRFValidationError
@@ -110,6 +112,14 @@ def get_serializer_context(self):
 
         return context
 
+    @swagger_auto_schema(
+        manual_parameters=[
+            openapi.Parameter("course", in_=openapi.IN_QUERY, type=openapi.TYPE_STRING)
+        ],
+    )
+    def retrieve(self, *args, **kwargs):
+        return super().retrieve(*args, **kwargs)
+
 
 # pylint: disable=too-many-ancestors
 class EnrollmentViewSet(