Add updating of support matrix to REALEASE.md

This will help future maintainers and prevent the table
from becoming huge again.

Author: oz123

RELEASE.md

@@ -3,7 +3,11 @@
 The Kubernetes Python client is released on an as-needed basis. The process is as follows:
 
 1. An issue is proposing a new release with a changelog since the last release
+1. Update the support matrix in README.md removing the oldest version and adding the
+   proposed release.
 1. All [OWNERS](OWNERS) must LGTM this release
-1. An OWNER runs `git tag -s $VERSION` and inserts the changelog and pushes the tag with `git push $VERSION`
+1. An OWNER runs `git tag -s $VERSION` and inserts the changelog and pushes
+   the tag with `git push $VERSION`
 1. The release issue is closed
-1. An announcement email is sent to `[email protected]` with the subject `[ANNOUNCE] kubernetes-python-client $VERSION is released`
+1. An announcement email is sent to `[email protected]`
+   with the subject `[ANNOUNCE] kubernetes-python-client $VERSION is released`