Improve Helm Chart Accessibility and Discoverability

[guillheu]

Currently, using this chart is more difficult than it has to be, since it is not being served by a proper helm chart repository (as far as I can tell).

Ideally, the helm release workflow should package the main branch's charts and create/update an index.yaml file and push those changes to the gh-pages branch.
I've noticed you have included the helm release workflow, but haven't created a gh-pages branch for it to push to. By creating a gh-pages branch and enabling github pages to serve the root directory of the gh-pages branch, the helm chart would be easily accessible at https://jellyfin.github.io/jellyfin-helm, making it way simpler to use the chart.
After that, I think it'd be good to list the chart on artifacthub.io. The process shouldn't take long and will make the chart far more discoverable.