Org reader: add semicolon to list of special chars

Semicolons are used as special characters in citations syntax.  This
ensures the correct parsing of Pandoc-style citations:

    [prefix; @key; suffix]

Previously, parsing would have failed unless there was a space or other
special character as the last <prefix> character.

src/Text/Pandoc/Readers/Org/Inlines.hs

@@ -127,7 +127,7 @@ inlines = trimInlinesF . mconcat <$> many1 inline
 
 -- treat these as potentially non-text when parsing inline:
 specialChars :: [Char]
-specialChars = "\"$'()*+-,./:<=>[\\]^_{|}~"
+specialChars = "\"$'()*+-,./:;<=>[\\]^_{|}~"
 
 
 whitespace :: OrgParser (F Inlines)