Address disabled numpydocs-validation checks

[pp-mo]

QA checks which we expect later to review + possibly remove.

The ultimate goal might be to have no 'ignores',
but we think that will probably be impractical in this case.

The controls are in the pyproject.toml "[tool.numpydoc_validation]" section e.g. these lines (as-after #568)

So-far chosen permanently disables :

• excluded specific dunder methods __eq__ / __ne__ / __repr__ (here)
• GL01 Permit summary line on same line as docstring opening quotes.
• GL02 Permit a blank line before docstring closing quotes.
• GL03 Allow double blank lines,
• SA01 Not all docstrings require a "See Also" section.
• ES01 Not all docstrings require an "Extended Summary" section.
• EX01 Not all docstrings require an "Examples" section.
• YD01 Not all docstrings require a "Yields" section.

Remaining temporarily disabled checks (number of errors triggered) :

• GL08 (*975) The object does not have a docstring
• PR01 (*149) Parameters ... not documented
• RT01 (*9) No Returns section found