Release 0.5.1

This is a minor update with docs, 3.8-compatible __version__, and a new build system.

What's Changed

• Update docs for basic task: getting tvd, northing and easting from md, inc, azi by @kinverarity1 in #65
• Add Deviation Polar Plot by @AlexanderJuestel in #69
• Modern build by @jokva in #73

New Contributors

• @kinverarity1 made their first contribution in #65
• @AlexanderJuestel made their first contribution in #69

Full Changelog: 0.5.0...0.5.1