docs: expand release docs, update authors

[wpbonelli]

• add myself to authors in CITATION.cff per @langevin-usgs' recommendation
• expand/clarify docs/make_release.md and scripts/README.md
  • automation of remaining manual steps in executables release simplifies steps before making a new flopy release

[codecov]

Codecov Report

Merging #1660 (ff28ca6) into develop (fb72098) will decrease coverage by 1.1%.
The diff coverage is n/a.

@@            Coverage Diff            @@
##           develop   #1660     +/-   ##
=========================================
- Coverage     72.7%   71.6%   -1.2%     
=========================================
  Files          252     253      +1     
  Lines        54554   55724   +1170     
=========================================
+ Hits         39714   39916    +202     
- Misses       14840   15808    +968     

Impacted Files	Coverage Δ
flopy/utils/mfreadnam.py	32.2% <0.0%> (-45.3%)	⬇️
flopy/utils/binaryfile.py	77.2% <0.0%> (-2.1%)	⬇️
flopy/pakbase.py	80.4% <0.0%> (-1.1%)	⬇️
flopy/utils/compare.py	2.9% <0.0%> (ø)
flopy/mbase.py	69.1% <0.0%> (+0.1%)	⬆️
flopy/export/shapefile_utils.py	90.5% <0.0%> (+0.2%)	⬆️
flopy/mf6/mfbase.py	79.6% <0.0%> (+0.2%)	⬆️
flopy/utils/flopy_io.py	78.2% <0.0%> (+0.4%)	⬆️
flopy/mf6/utils/generate_classes.py	16.3% <0.0%> (+0.4%)	⬆️
flopy/utils/get_modflow.py	63.9% <0.0%> (+0.9%)	⬆️
... and 2 more

[langevin-usgs]

Nice documentation.