Format docstrings so they pass pydocstyle's criteria

[JackKelly]

Detailed Description

We plan to use pydocstyle to automatically check that our docstrings conform to a standard format. It would be amazing to have help tweaking our existing docstrings to conform!

pydocstyle's list of criteria is here: http://www.pydocstyle.org/en/stable/error_codes.html

Here's the Pull Request (and discussion) about enabling pydocstyle for nowcasting_utils: openclimatefix/nowcasting_utils#23

[jacobbieker]

The PR showing the errors from the linter for SatFlow is here: #96

[jacobbieker]

Also, any updates should probably wait for #94 to be merged, as that removes ~5400 lines of code and a ton of files, and shrinks SatFlow a lot