v1.0 - PyQt6 PDF viewer

Significantly revised the "draft" pre-release script. Removed the "forward" and "backward" buttons since the pdf pages are already listed on the side to scroll through. Plus, they were bugged...

Added a menu to choose a pdf instead of using a hardcoded path to a pdf, which was done for testing purposes.

Overall, very simple yet working script that can be modified for anyone's pleasure.