Add more backup repos

README.md

@@ -11,5 +11,7 @@ The mirror proxy is [https://updates.jenkins-zh.cn/update-center.json](https://u
 
 This repo has been backuped in several places:
 
+* [GitHub](https://jenkins-zh.github.io/update-center-mirror/) is the main repo
 * [Gitee](https://jenkins-zh.gitee.io/update-center-mirror/)
-* [GitHub](https://jenkins-zh.github.io/update-center-mirror/)
+* [Gitlab](https://gitlab.com/jenkins-zh/update-center-mirror)
+* [Gitea](https://gitea.com/jenkins-zh/update-center-mirror/)