* move single-user uninstall to the end
this is not the default method of installation, and therefore irrelevant
for most users.
* move the backup restore instructions to the first step
for most users we can expect that the system-wide shell init files were
not ever touched, so we can as well tell them to do the most likely
thing.
from experience, while it's not necessarily safe to just mess with these
files, most people are simply confused by the complexity of
instructions.
* provide more detailed instructions for using `sudo vifs`
we can expect most beginners not to ever have used `vi`, and they will
probably need some hand-holding.
* express instructions as a script
Co-authored-by: wamirez <wamirez@protonmail.com>
Co-authored-by: Robert Hensing <roberth@users.noreply.github.com>
`/etc/bash.bashrc` is backed up as `/etc/bash.bashrc.backup-before-nix`,
but since other changes might have been introduced in the meantime we can't
just tell the user to revert.
placed in a subsection of the binary install, the instructions are hard
to find. putting them in a separate page that is shown in the table of
contents should make it easier for users to find what they need when
they need it.
