Rename master to main

Author: ikarldasan

RELEASE.md

@@ -48,12 +48,12 @@
 
 Releasing requires a particular set of permissions.
 
-* Approver role for the image promoter process ([kubernetes/k8s.io/blob/main/k8s.gcr.io/images/k8s-staging-capi-openstack/OWNERS](https://github.com/kubernetes/k8s.io/blob/master/k8s.gcr.io/images/k8s-staging-capi-openstack/OWNERS))
+* Approver role for the image promoter process ([kubernetes/k8s.io/blob/main/k8s.gcr.io/images/k8s-staging-capi-openstack/OWNERS](https://github.com/kubernetes/k8s.io/blob/main/k8s.gcr.io/images/k8s-staging-capi-openstack/OWNERS))
 * Tag push and release creation rights to the GitHub repository (team `cluster-api-provider-openstack-maintainers` in [kubernetes/org/config/kubernetes-sigs/sig-cluster-lifecycle/teams.yaml](https://github.com/kubernetes/org/blob/master/config/kubernetes-sigs/sig-cluster-lifecycle/teams.yaml))
 
 ## Staging
 
 There is a post-submit Prow job running after each commit on master which pushes a new image to the staging repo (`gcr.io/k8s-staging-capi-openstack/capi-openstack-controller:latest`). Following configuration is involved:
-* staging gcr bucket: [kubernetes/k8s.io/blob/main/k8s.gcr.io/manifests/k8s-staging-capi-openstack/promoter-manifest.yaml](https://github.com/kubernetes/k8s.io/blob/master/k8s.gcr.io/manifests/k8s-staging-capi-openstack/promoter-manifest.yaml)
+* staging gcr bucket: [kubernetes/k8s.io/blob/main/k8s.gcr.io/manifests/k8s-staging-capi-openstack/promoter-manifest.yaml](https://github.com/kubernetes/k8s.io/blob/main/k8s.gcr.io/manifests/k8s-staging-capi-openstack/promoter-manifest.yaml)
 * post-submit `post-capi-openstack-push-images` Prow job: [kubernetes/test-infra/blob/master/config/jobs/image-pushing/k8s-staging-cluster-api.yaml](https://github.com/kubernetes/test-infra/blob/master/config/jobs/image-pushing/k8s-staging-cluster-api.yaml)) (corresponding dashboard is located at [https://testgrid.k8s.io/sig-cluster-lifecycle-image-pushes#post-capi-openstack-push-images](https://testgrid.k8s.io/sig-cluster-lifecycle-image-pushes#post-capi-openstack-push-images))
 * Google Cloud Build configuration which is used by the Prow job: [kubernetes-sigs/cluster-api-provider-openstack/cloudbuild.yaml](https://github.com/kubernetes-sigs/cluster-api-provider-openstack/blob/master/cloudbuild.yaml)