Update build guidelines in readme

[33Fraise33]

Hello,

The build guidelines in the readme, are they still up to date? They are confusing (the dependencies are after the make command) and they do not work out of the box on newer operating systems like debian12.

This is what I have found for dependencies that work on bookworm, not sure if they are complete:

apt-get install build-essential devscripts debhelper fakeroot python3-all python3-docutils iproute2 python3-ipy python3-setuptools
apt-get install dh-python python3-all python3-setuptools python3-docutils
apt-get install ethtool bridge-utils python3-mako

i was unable to locate python3-gvgen in bookworm. but it seems that ifupdown2 currently works without for me.