Update gitlab links to 5d-chess/5d-chess-js
Most links in the application and in README lead to https://gitlab.com/5d-chess/chess-in-5d
which prevents gitpod from working and shows following warning message:
Project 'alexbay218/5d-chess-js' was moved to '5d-chess/5d-chess-js'. Please update any links and bookmarks that may still have the old path.