Reference solution code for Learn2Reg 2024 COMULISglobe (SHG-BF) chal…

…lenge (see README.md)

Removing the auto-generated 'example_*.png' files; run 'example.py' t…

…o recreate (platform dependent encoding in any case)

Option to supply a Random number generator (e.g. 'rng = np.random.def…

…ault_rng(12345)') for reproducible results when using 'random_angles'

Update README.md