This adds my standard inputrc to my home-manager configuration, via the
latter's readline module, and adds nix-shell detection to my bash prompt
string.
Additionally, nix-shell is wrapped in a shell function, so that entering
a nix-shell environment automatically runs bash as a subprocess where
appropriate, as the default environment spawned by nix-shell is not to
my liking.
Change-Id: Id5b1b9415a185ad9920f268c66de32d6ccc0b452
Reviewed-on: https://cl.tvl.fyi/c/depot/+/2146
Reviewed-by: multi <depot@in-addr.xyz>
Tested-by: BuildkiteCI