Missing documentation for sys/internal/counters

[jweissig]

Describe the bug
PR #7541 added new endpoints sys/internal/counters/tokens and sys/internal/counters/entities under sys/internal/counters but the corresponding documentation is missing from the System Backend area. This went live with Vault 1.3.

To Reproduce
Steps to reproduce the behavior:

1. Visit the System Backend
2. Look for sys/internal/counters, sys/internal/counters/tokens, or sys/internal/counters/entities
3. See they are missing

Expected behavior
Find the documentation.

I'll likely submit a PR for this but wanted to track it before I forgot.

[jefferai]

We don't usually document internal endpoints as we don't want others to use/rely on them. I'm not sure why two of them are documented.

[jweissig]

Cool, thanks Jeff. I'll just close this then. Thank for the heads up.