Detectree

- moved `_gaussain_kernel1d` from scipy to detectree codebase

- added postprocess func args and kwargs to `LidarToCanopy`

- added pre-commit
- updated to laspy 2.0.0 (with optional laszip)
- updated bumpversion to double quotes (Python black)
- updated docs build
- tests and release to pypi and github with github actions
- added github issue templates, pull request template and updated contributing docs
- using pydocstyle and black
- added lidar to canopy module
- using keyword-only arguments

- drop `num_blocks` argument of `compute_image_descriptor` and `compute_image_descriptor_from_filepath`