Fill-voids

-----

* refactor: update Dockerfile to use a more sensible directory structure
* docs: show how to use return\_fill\_count
* feat: return number of voxels filled in + 1D, 2D, and 3D support (2)
* perf: remove extra copy operation at the front (1)
* docs: add badge
* docs: touch up wording
* docs: add install instructions
* docs: change summary from Kimimaro

-----

* chore: add tqdm to test requirements
* docs: update algorithm description
* fix+test: throws exception on zero size array + test for it
* fix: only assign new stack location if FOREGROUND seen
* refactor: reduce code duplication
* docs: adjust documentation to comport with new scanline algorithm
* perf: reduce usage of stack
* fix+perf: scanline version working
* wip: scanline algorithm
* fix: rename requirements\_test.py -> requirements\_test.txt
* fix: add support for floating types
* fixdocs: image display broken
* feat: working fill\_voids
* docs: describe algorithm and potential improvements
* Initial commit