feat(information_management): Ability to link Knowledge Base article to a Project Milestone

ref: #426 #427

app/project_management/serializers/project_milestone.py

@@ -58,6 +58,14 @@ class ProjectMilestoneModelSerializer(
 
         return {
             '_self': item.get_url( request = self._context['view'].request ),
+            'knowledge_base': reverse(
+                "v2:_api_v2_model_kb-list",
+                request=self._context['view'].request,
+                kwargs={
+                    'model': self.Meta.model._meta.model_name,
+                    'model_pk': item.pk
+                }
+            ),
         }