Release bot

[nitrocode]

This should

• allow no-op changes (e.g. updating documentation or other changes without bumping versions)
• prevent having to bump chart versions manually. I.e. It should default to minor bump unless patch label is present

Options

1. See https://github.com/cloudposse/terraform-aws-ecr/blob/master/.github/auto-release.yml and https://github.com/cloudposse/terraform-aws-ecr/blob/master/.github/workflows/auto-release.yml for inspiration.
2. Also see https://github.com/marketplace/actions/helm-chart-releaser

[GenPage]

@nitrocode Is this still relevant after #244?

[nitrocode]

#244 took care of the first bullet (allow no-op changes).

We still need a way to add changes to the chart without manual chart version bumps.