[JOSS] Paper edits, etc.

[jGaboardi]

This PR:

• provide minor grammar, vocabulary, etc. edits to the manuscript (some of the edits need to be made in README.md and the docs, as well)
• updates the MovingPandas citation
• updates the original PySAL citation and provides the most recent PySAL citation

xref: openjournals/joss-reviews#4021

[codecov-commenter]

Codecov Report

Merging #13 (6e960ee) into main (c5a8b60) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##             main      #13   +/-   ##
=======================================
  Coverage   93.56%   93.56%           
=======================================
  Files          22       22           
  Lines        1617     1617           
=======================================
  Hits         1513     1513           
  Misses        104      104           

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