Option to ignore coarse dimensions when partitioning

[NoraLoose]

This PR adds a parameter include_coarse_dimensions to partition() and partition_netcdf(). If set to False, the dimensions eta_coarse and xi_coarse are ignored during the partitioning process.

• Closes Partitioning fails due to divisibility of coarse dimensions #330
• Tests added
• Passes pre-commit run --all-files
• Changes are documented in docs/releases.md
• New functions/methods are listed in docs/api.rst
• New functionality has documentation

[review-notebook-app]

Check out this pull request on 

See visual diffs & provide feedback on Jupyter Notebooks.

---

Powered by ReviewNB

[ScottEilerman]

Looks good!

The most irrelevant nitpick: this line in the PR description is backwards:

If set to True, the dimensions eta_coarse and xi_coarse are ignored during the partitioning process.

I forget if the PR descriptions get auto-included anywhere but might as well fix it quick, then good to merge!

[NoraLoose]

The most irrelevant nitpick: this line in the PR description is backwards:

If set to True, the dimensions eta_coarse and xi_coarse are ignored during the partitioning process.

I forget if the PR descriptions get auto-included anywhere but might as well fix it quick, then good to merge!

Thanks, good catch -- fixed!