Improved Makefile support

[Turysaz]

I have the language-make package installed and it mostly works (target declarations, strings and comments are highlighted), but the highlighting of variables is missing.

Also, I find the highlighting of the targets not very obvious. Maybe they could be displayed in a color that makes them stand out a little more.

I'd probably fix this myself and open a PR some day in the future, but at the moment I don't have time for doing it. Maybe someone else has? ;-)

PS: Thank you for this cool theme! Nice work!

Screenshots
Hackerman syntax:

Run Time syntax (for reference):