File restructuring and OOP
As the branch name says:
- This ticket restructures the files related to the GUI (GUI.py, tab1.py, tab2.py, tab3.py) and moves them into src/
- This ticket makes the content of both GUI.py and Database.py into functions
- This ticket imports the files Database.py and GUI.py in order to create the database and load the GUI from Main.py
Edited by Darcey Haddow