Fix release process phrasing (nginx#1204)

Ensure that the helm chart version is bumped on release. This was incorrectly removed in a previous PR.

Author: miledxz

docs/developer/release-process.md

@@ -33,7 +33,7 @@ To create a new release, follow these steps:
 5. Create a release branch with a name that follows the `release-X.Y` format.
 6. Prepare and merge a PR into the release branch to update the repo files for the release:
     1. Update the Helm [Chart.yaml](/deploy/helm-chart/Chart.yaml): the `appVersion` to `X.Y.Z`, the icon and source
-       URLs to point at `vX.Y.Z`.
+       URLs to point at `vX.Y.Z`, and bump the `version`.
     2. Adjust the `VERSION` variable in the [Makefile](/Makefile) and the `NGF_TAG` in the
        [conformance tests Makefile](/conformance/Makefile) to `X.Y.Z`.
     3. Update the tag of NGF container images used in the Helm [values.yaml](/deploy/helm-chart/values.yaml) file, the