allow citekeys in footnotes

Author: fmoralesc

syntax/pandoc.vim

@@ -406,7 +406,7 @@ call s:WithConceal("footnote", 'syn match pandocFootnoteDefHead /\^\[/ contained
 call s:WithConceal("footnote", 'syn match pandocFootnoteDefTail /\]/ contained containedin=pandocFootnoteDef', 'conceal')
 
 " regular footnotes
-syn region pandocFootnoteBlock start=/\[\^.\{-}\]:\s*\n*/ end=/^\n^\s\@!/ contains=pandocReferenceLabel,pandocReferenceURL,pandocLatex,pandocPCite,pandocStrong,pandocEmphasis,pandocNoFormatted,pandocSuperscript,pandocSubscript,pandocStrikeout,pandocEnDash,pandocEmDash,pandocNewLine,pandocStrongEmphasis,pandocEllipses,pandocBeginQuote,pandocEndQuote,@Spell skipnl
+syn region pandocFootnoteBlock start=/\[\^.\{-}\]:\s*\n*/ end=/^\n^\s\@!/ contains=pandocReferenceLabel,pandocReferenceURL,pandocLatex,pandocPCite,pandocCiteKey,pandocStrong,pandocEmphasis,pandocNoFormatted,pandocSuperscript,pandocSubscript,pandocStrikeout,pandocEnDash,pandocEmDash,pandocNewLine,pandocStrongEmphasis,pandocEllipses,pandocBeginQuote,pandocEndQuote,@Spell skipnl
 syn match pandocFootnoteBlockSeparator /:/ contained containedin=pandocFootnoteBlock
 syn match pandocFootnoteID /\[\^.\{-}\]/ contained containedin=pandocFootnoteBlock
 call s:WithConceal("footnote", 'syn match pandocFootnoteIDHead /\[\^/ contained containedin=pandocFootnoteID', 'conceal cchar='.s:cchars["footnote"])