Better cleanup with reset playbook (#353)

* Better cleanup with reset playbook

The install playbook adds some convenience commands into the user's
.bashrc. If K3s is uninstalled, these commands produce errors. Since
they are eaily identifiable, it is trivial to remove them to improve
the user's experience.

Signed-off-by: Marko Vukovic <8951449+anon-software@users.noreply.github.com>