Add GitHub workflow for PyPI releases

[maxrjones]

Description of proposed changes

Part of #104

Based on https://github.com/pydata/xarray/blob/main/.github/workflows/pypi-release.yaml and https://github.com/GenericMappingTools/pygmt/blob/3ec107b6773c6969e1f6103151bffd1eae9f27ad/.github/workflows/publish-to-pypi.yml#L39-L46

To-do:

• Test with TestPyPI
• Document workflow

Fixes #

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 97.97%. Comparing base (d409930) to head (12ecb3f).
Report is 70 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #108   +/-   ##
=======================================
  Coverage   97.97%   97.97%           
=======================================
  Files           5        5           
  Lines         198      198           
  Branches       35       35           
=======================================
  Hits          194      194           
  Misses          4        4           

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[maxrjones]

Thanks for the reviews on this, @weiji14 and @andersy005!