Add release info

Author: jotak

docs/RELEASE.md

@@ -0,0 +1,62 @@
+## Releasing NetObserv CLI
+
+### Tagging & creating a draft release
+
+This is the process of releasing the NetObserv CLI on GitHub. First, tag from the release branch that you want to publish (make sure you're up to date):
+
+```bash
+git fetch upstream
+git reset --hard upstream/(release branch)
+version="v0.0.6"
+git tag -a "$version" -m "$version"
+git push upstream --tags
+```
+
+When the tag is pushed, a release action is triggered on GitHub: https://github.com/netobserv/network-observability-cli/actions/workflows/release.yml.
+
+When the job completes, you should see a new draft release in https://github.com/netobserv/network-observability-cli/releases.
+
+### Krew
+
+If you haven't already, fork and clone the krew-index repo from https://github.com/kubernetes-sigs/krew-index.
+
+From there, you'll find the NetObserv plugin info in `plugins/netobserv.yaml`.
+
+Copy and paste the YAML snippet provided in draft release on GitHub, into that `netobserv.yaml` file.
+
+To test it, first download the tgz archive from the GitHub release (see the `netobserv-cli.tar.gz` link under "Assets").
+
+Then:
+
+```bash
+# uninstall any previous version of the plugin
+kubectl krew uninstall netobserv
+# reinstall using the current manifest and archive
+kubectl krew install --manifest=plugins/netobserv.yaml --archive=/path/to/netobserv-cli.tar.gz
+kubectl netobserv version
+# output: Netobserv CLI version <the new version>
+
+# smoke-test on a live cluster
+kubectl netobserv flows
+```
+
+NB: The process to publish a plugin update is also documented in https://krew.sigs.k8s.io/docs/developer-guide/release/updating-plugins/.
+
+### Publish the GitHub release
+
+When tests are OK, edit the draft release in GitHub:
+- Remove the text template
+- Auto-generate the release note
+- Check the "Set as the latest release" box
+- Click Publish
+
+### Krew again
+
+Finally, commit the YAML changes and open a pull request:
+
+```bash
+git commit -a -s -m "Bump netobserv $version"
+git push origin HEAD:bump-$version
+```
+
+Note: the first time, you may need to sign the CLA for the Linux Foundation / CNCF. Check your PR for any additional step to take.