Need a helm chart linter and releaser to github.io via Github Actions

[jessebot]

Is your feature request related to a problem? Please describe.
The helm chart is currently only set to release to hashicorp's own helm repos.

Describe the solution you'd like
We should setup a couple of github action workflows to release this chart to openbao.github.io (but only when something in charts dir has changed), as well as lint the chart on pull requests. We can follow the examples here:

• https://github.com/openbao/openbao-helm/blob/main/.github/workflows/lint-chart.yml
• https://github.com/openbao/openbao-helm/blob/main/.github/workflows/release-chart.yml

Describe alternatives you've considered
In the future, we can release this to somewhere else, but for now github.io is the easiest to move forward with.

[jessebot]

You can assign this to me.