sig-contribex: add maintainers repo

Author: nikhita

sig-contributor-experience/README.md

@@ -101,6 +101,7 @@ Manages and controls Github permissions, repos, and groups, including Org Member
   - [kubernetes-client/.github](https://github.com/kubernetes-client/.github/blob/master/OWNERS)
   - [kubernetes-csi/.github](https://github.com/kubernetes-csi/.github/blob/master/OWNERS)
   - [kubernetes-sigs/.github](https://github.com/kubernetes-sigs/.github/blob/master/OWNERS)
+  - [kubernetes-sigs/maintainers](https://github.com/kubernetes-sigs/maintainers/blob/main/OWNERS)
   - [kubernetes/.github](https://github.com/kubernetes/.github/blob/master/OWNERS)
   - [kubernetes/community/github-management](https://github.com/kubernetes/community/blob/master/github-management/OWNERS)
   - [kubernetes/kubernetes-template-project](https://github.com/kubernetes/kubernetes-template-project/blob/master/OWNERS)

sigs.yaml

@@ -1333,6 +1333,7 @@ sigs:
     - https://raw.githubusercontent.com/kubernetes-client/.github/master/OWNERS
     - https://raw.githubusercontent.com/kubernetes-csi/.github/master/OWNERS
     - https://raw.githubusercontent.com/kubernetes-sigs/.github/master/OWNERS
+    - https://raw.githubusercontent.com/kubernetes-sigs/maintainers/main/OWNERS
     - https://raw.githubusercontent.com/kubernetes/.github/master/OWNERS
     - https://raw.githubusercontent.com/kubernetes/community/master/github-management/OWNERS
     - https://raw.githubusercontent.com/kubernetes/kubernetes-template-project/master/OWNERS