Merge pull request #2489 from brooksn/dev-docs-updates

Update docs: changes to creating a release

developer-docs/upgrading_kubernetes.md

@@ -56,10 +56,13 @@ Next, we need to create a release candidate (RC). The Drone (CI) process that bu
 
 * Click "Releases"
 * Click "Draft new release"
+* Select the target branch
 * Enter the desired version into the "Tag version" box. 
     * Example tag: `v1.21.4+rke2r2`
     * **NOTE** Make sure to create the tag against the correct release branch. In the example above, that would map to release branch `release-1.21`.
 
+Ensure "prerelease" checkbox is selected.
+
 CI will run and build the release assets as well as kick off an image build for [RKE2 Upgrade images](https://hub.docker.com/r/rancher/rke2-upgrade/tags?page=1&ordering=last_updated).
 
 _**Note: Once an RC is released for QA, the release branch associated with the RC is now considered frozen until the final release is complete. If additional PRs need to get merged in after an RC, but before the final release, you should notify the RKE2 team of this immediately. After merging, an additional RC will need to be released for QA.**_
@@ -70,6 +73,7 @@ Along with creating a new RKE2 release, we need to trigger a new build of the as
 
 * Click "Releases"
 * Click "Draft new release"
+* Select the target branch
 * Enter the desired version into the "Tag version" box. 
     * Example tag: `v1.21.4-rc1+rke2r1.testing.0`
     * The first part of the tag here must match the tag created in the RKE2 repo.