Add Helm chart to repository with CI

[diademiemi]

Hi Checkmk team!

We want to deploy Checkmk within K3S as a standard deployment. For this we want to use Helm to install and configure software, which Checkmk did not yet have.

I made this helm chart and have used it to deploy Checkmk in networks, multi-site too.

I'm creating a PR here for if it's desired to also have this upstream. I provided a GitHub workflow to use GitHub Pages as a Helm repository (a gh-pages branch will need to be created). Different ways to publish it like done with the Checkmk cluster agent could be done too of course.

The file charts/checkmk/README.md contains documentation for the chart, this is automatically generated with helm-docs

[berlincount]

Thanks for the work, it works largely as expected under ArgoCD!

• the PVC (if enabled) doesn't come up by itself, requires setting all values for successful sync
• the secret needed to be manually created

I recommend merging this PR and basing further work on it; I was able to get a working check_mk installation via ArgoCD within minutes.