* fix(mypy): type annotations for cipher algorithms
* Update mypy workflow to include cipher directory
* fix: mypy errors in hill_cipher.py
* fix build errors
* introduced shuffled_shift_cipher.py in /ciphers
* made requested changes
* introduced doctests, type hints
removed __make_one_digit()
* test_end_to_end() inserted
* Make test_end_to_end() a test ;-)