Improve Secrets Webhook Metrics documentation

[kajov]

Preflight Checklist

• I have searched the issue tracker for an issue that matches the one I want to file, without success.

Problem Description

Missing clear description/list of possible or enabled metrics after metrics and service monitor is enabled.

Due to to changes thru out the years, documentation no longer reflects and or lists of what can be expected when metrics endpoint is enabled.

Proposed Solution

• Create a list of metrics labels that will be enabled by default and possible ones that can be enabled.

• Update documentation with metrics endpoint readability, that service that has been created does not show metrics but you have to port-forward each pod and access their /metrics endpoint

Alternatives Considered

No response

Additional Information

No response