Reimplement citeproc-style-note-style as a function

citeproc-style.el

@@ -62,6 +62,10 @@ USES-YS-VAR is non-nil iff the style uses the YEAR-SUFFIX
   cite-layout cite-layout-attrs locale-opts macros terms
   uses-ys-var date-text date-numeric locale)
 
+(defun citeproc-style-cite-note (style)
+  "Return whether csl STYLE is a note style."
+  (string= (citeproc-style-category style) "note"))
+
 (defun citeproc-style-parse (style)
   "Return the parsed representation of csl STYLE.
 STYLE is either a path to a style file or a style as a string.