Update content/en/docs/concepts/extend-kubernetes/api-extension/_index.md

Co-authored-by: Tim Bannister <[email protected]>

Author: pegasas

content/en/docs/concepts/extend-kubernetes/api-extension/_index.md

@@ -13,6 +13,6 @@ Custom resources are extensions of the Kubernetes API. Kubernetes provides two w
 - The [aggregation layer](/docs/concepts/extend-kubernetes/api-extension/apiserver-aggregation/) sits behind the primary API server, which acts as a proxy.
   This arrangement is called API Aggregation(AA), which allows you to provide
   specialized implementations for your custom resources by writing and
-deploying your own API server.
-The main API server delegates requests to your API server for the custom resources that you handle,
-making them available to all of its clients.
+  deploying your own API server.
+  The main API server delegates requests to your API server for the custom APIs that you specify,
+  making them available to all of its clients.