new setup.sh behaviour breaks installing/reinstalling from a local custom fork

The new behaviour of setup.sh is super unfriendly.

Running setup just re-clones the main repo to ~/.local/winapps-src and intalls from there - regardless of the repo being cloned locally already.

Not only is this doubling up on cloning, but BIG issue here is when you are wanting to install winapps from a custom local fork for testing . The current behaviour effectively ignores all local code, which forces all custom changes to be manually re-added each and every time setup is run.

I really think that setup should try to install from any local repo source first and certainly not ignore or overwrite customisations made to any local code. (This nearly caught me out testing a new PR, as I was thinking I was testing my own new code and all the while I wasn't testing anything new. )