contrib/debootstrap: Add initial support for Tanglu

This will add support for Tanglu, a Debian based Linux-distribution.

Docker-DCO-1.1-Signed-off-by: Matthias Klumpp <matthias@tenstral.net> (github: Ximion)
Merge pull request #4246 from Ximion/master

contrib/debootstrap: Add initial support for Tanglu