List operator tools in alphabetical order

This is to update operator web page to
list operator tools in alphabetical order as well as other
minor improvements.

Author: chenxuc

content/en/docs/concepts/extend-kubernetes/operator.md

@@ -103,26 +103,27 @@ as well as keeping the existing service in good shape.
 ## Writing your own Operator {#writing-operator}
 
 If there isn't an Operator in the ecosystem that implements the behavior you
-want, you can code your own. In [What's next](#what-s-next) you'll find a few
-links to libraries and tools you can use to write your own cloud native
-Operator.
+want, you can code your own. 
 
 You also implement an Operator (that is, a Controller) using any language / runtime
 that can act as a [client for the Kubernetes API](/docs/reference/using-api/client-libraries/).
 
+Following are a few libraries and tools you can use to write your own cloud native
+Operator.
+
+{{% thirdparty-content %}}
 
+* [kubebuilder](https://book.kubebuilder.io/)
+* [KUDO](https://kudo.dev/) (Kubernetes Universal Declarative Operator)
+* [Metacontroller](https://metacontroller.app/) along with WebHooks that
+  you implement yourself
+* [Operator Framework](https://operatorframework.io)
 
 ## {{% heading "whatsnext" %}}
 
 
 * Learn more about [Custom Resources](/docs/concepts/extend-kubernetes/api-extension/custom-resources/)
 * Find ready-made operators on [OperatorHub.io](https://operatorhub.io/) to suit your use case
-* Use existing tools to write your own operator, eg:
-  * using [KUDO](https://kudo.dev/) (Kubernetes Universal Declarative Operator)
-  * using [kubebuilder](https://book.kubebuilder.io/)
-  * using [Metacontroller](https://metacontroller.app/) along with WebHooks that
-    you implement yourself
-  * using the [Operator Framework](https://operatorframework.io)
 * [Publish](https://operatorhub.io/) your operator for other people to use
 * Read [CoreOS' original article](https://web.archive.org/web/20170129131616/https://coreos.com/blog/introducing-operators.html) that introduced the Operator pattern (this is an archived version of the original article).
 * Read an [article](https://cloud.google.com/blog/products/containers-kubernetes/best-practices-for-building-kubernetes-operators-and-stateful-apps) from Google Cloud about best practices for building Operators