SSH access instructions

[KilllerRabbbit]

I'd like to suggest that the installation instructions are expanded with the instructions how to find the installation directory and issue a command over ssh.

There are various tailscale features (like subnet routing) that anyway require ssh.

The GUI component is also not very reliable so far (Login link didn't work in the beginning, now the GUI doesn't work any more although Tailscale is connected and works fine) so ssh is rather necessary also to control the basic functionalities.

Subset of text from https://github.com/tailscale/tailscale-qpkg/tree/update should be enough.

[austinliuu]

Same, especially given the current web control panel is not working for me (shows "not authenticated")