Geocat-comp

This release includes:
- Doc Fixes
- Updates to Skewt-params
- other miscellany.

Release notes:
- Fixed import issues for `cftime` in v2021.08.0.
- Functions `dewtemp`, `heat_index`, `relhum`, `relhum_ice`, and `relhum_water` combined together under `meteorology` module.
- `climatology` module renamed to `climatologies`.
- `interp_hybrid_to_pressure` module renamed to `interpolation`.
- Corresponding documentation changes for module refactoring done.
- Slight changes for internal and user API documentation done.

Release notes:
- Python 3.6 support removed.
- Corresponding documentation changes done.
- Small correction on Internal APi documentation.

Release notes:
- New functions: `calender_average` and `climatology_average`
- Corresponding documentation added.
- Errors with version number and a few imports fixed.

Release notes:
- Dask compatibility improvements on several functions such as `dewtemp`, `heat_index`, and `relhum` function family
- Bug fixes for edge cases in `fourier_filters`
- Bug fixes in several `crop` module functions
- Documentation improvements for internal API
- Refactoring for improved code readability

Release notes:
- Optimizations to `month_to_season`
- Workaround for Metpy's Issue with 4D Xarray in `interp_hybrid_to_sigma`