Retitle “Kubernetes API Aggregation Layer” concept

Tim Bannister · Tim Bannister · commit 075fdf2e376c · 2021-08-04T22:28:54.000+01:00
The old title “Extending the Kubernetes API with the aggregation layer”
sounds more like a task page than a concept, so I reworded.
diff --git a/content/en/docs/concepts/extend-kubernetes/api-extension/apiserver-aggregation.md b/content/en/docs/concepts/extend-kubernetes/api-extension/apiserver-aggregation.md
@@ -1,5 +1,5 @@
 ---
-title: Extending the Kubernetes API with the aggregation layer
+title: Kubernetes API Aggregation Layer
 reviewers:
 - lavalamp
 - cheftako
