We also clarify the procedure a little by avoiding the use of nano,
among other things. It might come as a surprise, but nano is not
really intuitive or easy to use for some people, use the lowest common
denominator instead (cat).

This is to please the linter, but it is also to make it look correctly
indented in the rendered version.

A fellow Debian developer recommended this on Debian Planet, I haven't
test it myself.

... that's as much i could do in a reasonable amount of time, but
there's a lot of references to it everywhere. There's certainly still
stuff referencing git.tpo as well.

Hi!  Please merge this only if you think it will be helpful, and
feel free to clean it up or edit it any way you want.

Turns out that we don't use the `postgresql` module at all right now,
and `dip::database` has been removed. We have an Installation section now.