Update the branch name from master to main

Author: vaibhav2107

code-of-conduct.md

@@ -1,6 +1,6 @@
 # Kubernetes Community Code of Conduct
 
-Kubernetes follows the [CNCF Code of Conduct](https://github.com/cncf/foundation/blob/master/code-of-conduct.md).
+Kubernetes follows the [CNCF Code of Conduct](https://github.com/cncf/foundation/blob/main/code-of-conduct.md).
 
 Instances of abusive, harassing, or otherwise unacceptable behavior may be reported by contacting
 the [Kubernetes Code of Conduct Committee](./committee-code-of-conduct) via <conduct@kubernetes.io>.