ci/README: Document command used to find stale version

Author: nhooyr

ci/README.md

@@ -19,6 +19,8 @@ Make sure you have `$GITHUB_TOKEN` set and [hub](https://github.com/github/hub)
    2. Update in [./doc/install.md](../doc/install.md)
    3. Update in [./ci/helm-chart/README.md](../ci/helm-chart/README.md)
       - Remember to update the chart version as well on top of appVersion in `Chart.yaml`.
+      - Run `rg -g '!yarn.lock' -g '!*.svg' '3\.7\.5'` to ensure all values have been
+        changed. Replace the numbers as needed.
 2. GitHub actions will generate the `npm-package`, `release-packages` and `release-images` artifacts.
    1. You do not have to wait for these.
 3. Run `yarn release:github-draft` to create a GitHub draft release from the template with