Update link of "Operator White Paper" on operator.md page

Update the link to the main branch to update the paper from "Review Version" to "Final Version"

Author: able8

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

@@ -129,7 +129,7 @@ operator.
 
 
 * Read the {{< glossary_tooltip text="CNCF" term_id="cncf" >}}
-  [Operator White Paper](https://github.com/cncf/tag-app-delivery/blob/eece8f7307f2970f46f100f51932db106db46968/operator-wg/whitepaper/Operator-WhitePaper_v1-0.md).
+  [Operator White Paper](https://github.com/cncf/tag-app-delivery/blob/main/operator-wg/whitepaper/Operator-WhitePaper_v1-0.md).
 * 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
 * [Publish](https://operatorhub.io/) your operator for other people to use