Document <cite command>labeldate formats?

[moewew]

See https://golatex.de/viewtopic.php?p=115990#p115990. The authoryear styles define

biblatex-ext/ext-authoryear.cbx

Lines 26 to 30 in 9d79baf

	\DeclareFieldFormat{citelabeldate}{#1}
	\DeclareFieldFormat{parencitelabeldate}{#1}
	\DeclareFieldFormat{textcitelabeldate}{#1}
	\DeclareFieldFormat{footcitelabeldate}{#1}
	\DeclareFieldAlias{footcitetextlabeldate}{footcitelabeldate}

and use those formats

biblatex-ext/ext-authoryear.cbx

Lines 32 to 38 in 9d79baf

	\renewbibmacro*{cite:labeldate+extradate}{%
	\iffieldundef{labelyear}
	{}
	{\printtext[extblx@inner\blx@delimcontext delims]{%
	\printtext[bibhyperref]{%
	\printtext[\blx@delimcontext labeldate]{%
	\printlabeldateextra}}}}}

Check that they are safe to redefine for users and document them if that is the case.