There's enough little things necessary here, that you may forget one or two, so I've documented all the files you need to create/change to get RenovateBot automatically creating PRs for your helm chart. This flow uses the renovatebot/github-action.
Set the repositories to your own repo. In this case, jessebot/vaultwarden
references github.com/jessebot/vaultwarden.
The regexManagers
bumps the Chart.yaml appVersion
, based on the command in the Chart.yaml below. See docs.