Sunbeam documentation does not state where the verbose logs can be found

Normally they are found in `$HOME/snap/openstack/common/logs/sunbeam-*.log`

The [Inspecting the cluster documentation page](https://canonical-openstack.readthedocs-hosted.com/en/latest/how-to/troubleshooting/inspecting-the-cluster/) does not mention it.

Maybe we can also add the verbose logs can be obtained in stdout via the `-v` flag

Start with the Inspecting the cluster documentation page linked in the issue. Document the usual verbose log location at $HOME/snap/openstack/common/logs/sunbeam-*.log and explain that the -v flag can also show verbose logs on stdout; done when both ways to find the logs are clear on the page.

Written by the indexing model from the issue text.