Brave browser profile between containers error fix

[MarcusHoltz]

Update documentation to include Brave browser profile error fix:

https://neko.m1k1o.net/docs/v3/troubleshooting#browser-profile-not-starting

The docker compose command below lets you re-use brave profiles between containers.
It removes Brave's lock files every time the container starts, so Brave never thinks another process is using the profile.

command: sh -c "rm -f /home/neko/.config/brave/SingletonLock /home/neko/.config/brave/SingletonCookie /home/neko/.config/brave/SingletonSocket && exec /usr/bin/supervisord -c /etc/neko/supervisord.conf"

Thanks!