Please add installation instructions

[jleaders]

Please explain how to install deb-cup in your Readme.md

[SanZamoyski]

I had some problems, but now it runs (not sure it works):

cd deb-cup/
make
mkdir /home/san/.config/deb-cup
touch /home/san/.config/deb-cup/recent
sudo apt install yad
bin/deb-cup 

[jleaders]

It seems to work fine! I made some debs