Updated makefile to override link to executable

Currently make clean is not sufficient to subsequently execute make or similar without getting an error.
Like that Error: cabal: Path '~/.cabal/bin/cetera-main' already exists.
This changes the makefile so that the link is now overwritten.
It is still debatable whether the currently selected option always or the manual selection prompt is better.
If we choose the second one, the error will only occur if there is already a link and we choose the option n in the prompt.