DM-42077: Fix numpydoc doc strings

[timj]

Checklist

• ran Jenkins
• added a release note for user-visible changes to doc/changes

[codecov]

Codecov Report

Attention: 5 lines in your changes are missing coverage. Please review.

Comparison is base (d550cd6) 87.60% compared to head (5eb0dc3) 87.60%.

Files	Patch %	Lines
python/lsst/daf/butler/datastores/fileDatastore.py	33.33%	2 Missing ⚠️
...hon/lsst/daf/butler/datastores/chainedDatastore.py	50.00%	1 Missing ⚠️
...on/lsst/daf/butler/datastores/inMemoryDatastore.py	50.00%	1 Missing ⚠️
python/lsst/daf/butler/json.py	66.66%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #922      +/-   ##
==========================================
- Coverage   87.60%   87.60%   -0.01%     
==========================================
  Files         295      295              
  Lines       38259    38254       -5     
  Branches     8088     8088              
==========================================
- Hits        33516    33511       -5     
  Misses       3539     3539              
  Partials     1204     1204              

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