Apparently the helm chart and the oauth2-proxy documentation are not
consistent.

References:
https://artifacthub.io/packages/helm/oauth2-proxy/oauth2-proxy

The proxy secret wasn't generated properly, it has to be base64 encoded.
Therefore the following command is recommended:

```shell
cat /dev/urandom | tr -dc 'a-zA-Z0-9' | fold -w 32 | head -n 1 | base64
```

References:
https://oauth2-proxy.github.io/oauth2-proxy/docs/configuration/overview#generating-a-cookie-secret

This patch introduces calver releases to the repository, this is just to
document progress and helps to navigate the changes in the future.

This patch adds a service monitor for longhorn

This patch fixes the broken kustomize based on the allow-from-ingress
shared network policy document.

This patch adds a new network policy to allow traffic from the
monitoring namespace to access the exporter endpoints. Since it's not
using allow right now, prometheus reports target down.

The template still contained a wrong namespace name which was a copied
from a policy template. Since the switch to a simple shared document the
namespace name is filled in by kustomize instead and therefore has to be
removed from the shared file.

The namespace selector topic in the helm chart is a bit of a mess, but
github issues seem to help:

https://github.com/prometheus-operator/prometheus-operator/issues/3636

Previously there was a full copy of the values yaml around in the values
section of the release. This patch cuts it down only to the modified
parts and a few options that should be interesting in the future.

Turns out, doesn't work as expected.

This reverts commit c11ca652.

Currently chartmuseum only creates massive load with no benefit.
Removing it, sounds like a good idea.