Move Garbage Collection topic. (#2874)

* Move Garbage Collection topic.

* Fix included file.

_data/concepts.yml

@@ -14,14 +14,6 @@ toc:
     - docs/concepts/overview/working-with-objects/annotations.md
   - docs/concepts/overview/kubernetes-api.md
 
-- title: Kubernetes Objects
-  section:
-  - title: Pods
-    section:
-  - title: Controllers
-    section:
-    - docs/concepts/abstractions/controllers/garbage-collection.md
-
 - title: Workloads
   section:
   - title: Pods
@@ -33,6 +25,7 @@ toc:
     section:
     - docs/concepts/workloads/controllers/statefulset.md
     - docs/concepts/workloads/controllers/petset.md
+    - docs/concepts/workloads/controllers/garbage-collection.md
   - title: Jobs
     section:
     - docs/concepts/jobs/run-to-completion-finite-workloads.md