Add setting of NEXTCLOUD_SERVER and NEXTCLOUD_INFO_APPS for metrics exporter and clean up docs

[jessebot]

Pull Request

Description of the change

This is an update to the metrics section of the values.yaml. This PR covers:

• adds optionally setting NEXTCLOUD_SERVER via the metrics.server parameter, instead of allowing the chart to template it out from the k8s service. If not provided, we still use the service name

• adds setting NEXTCLOUD_INFO_APPS via the metrics.info.apps parameter, which "Enables gathering of apps-related metrics". Defaults to false as it does in the actual container.

• adds metrics.replicaCount to the README, as it was missing

• formats the tables in the README (because my linter did it by default 😅 )

Benefits

This allows users to get more granular when playing with the metrics exporter container.

Possible drawbacks

none that I can see immediately. open to chatting as usual :)

Applicable issues

not sure we have any issues on this yet?

Additional information

See docs here: https://github.com/xperimental/nextcloud-exporter?tab=readme-ov-file#environment-variables

Checklist

• DCO has been signed off on the commit.
• Chart version bumped in Chart.yaml according to semver.
• (optional) Variables are documented in the README.md