* huge performance boost for creating `PNG`s (up to 2 orders of magnitude - 100x)
* cleanup
* refactorings
bash
> time python3 -m hashpic 'Hashpic rocks!' -d --shake256 --length 255
before
python3 -m hashpic 'Hashpic rocks!' -d --shake256 --length 255 24,65s user 0,08s system 99% cpu 24,787 total
after
python3 -m hashpic 'Hashpic rocks!' -d --shake256 --length 255 0,25s user 0,05s system 79% cpu 0,375 total
> time python3 -m hashpic 'Hashpic rocks!' -d --blake2b
before
python3 -m hashpic 'Hashpic rocks!' -d --blake2b 1,31s user 0,05s system 98% cpu 1,372 total
after
python3 -m hashpic 'Hashpic rocks!' -d --blake2b 0,19s user 0,04s system 78% cpu 0,303 total