Mismatched variable name part-number in apa.csl and the locales

[zepinglee]

styles/apa.csl

Lines 607 to 610 in d9989a2

	<group delimiter=" ">
	<label variable="part-number" form="short" text-case="capitalize-first"/>
	<text variable="part-number"/>
	</group>

The current version of apa.csl has a cs:label element that calls part-number variable, which was introduced in #6709. However the latest en-US locale doesn't have such a part-number term. Instead there is a part term (locales-en-US.xml#L274-L277). So I guess this is a typo. @bwiernik.

I then check the schema and documentation. There is a part variable in the schema (v1.0 branch, schemas/input/csl-data.json#L375-L377) but its name is part-number in the documentation (specification.rst#L2903-L2904). I've also found the following mismatched variable names in the documentation.

schema	documentation
part	part-number
printing	printing-number
supplement	supplement-number

[zepinglee]

This is found when I try to fix citeproc-py/citeproc-py#146.