Add documentation for running diagnostics from terminal
The current documentation specifies how to collect logs manually but we can also generate diagnostics from terminal. With turris/os/packages!743 (merged) this should be even easier:
turris-diagnostics | gzip > diag.gz
The documentation should probably state:
- How to generate diagnostics
- How to get them from router over SSH
- That user should remove them afterwards so they are not taking up space or that he should generate them in /tmp