E-mail addresses are incorrectly interpreted as bracketed citations #424
Description
Writing [translation@castb.org](mailto:translation@castb.org) with citations option enabled is interpreted as a citation:
$ markdown-cli citations=true <<< '[translation@castb.org](mailto:translation@castb.org)'\markdownRendererDocumentBegin
\markdownRendererCite{1}+{translation}{}{castb.org}(mailto:translation@castb.org)\markdownRendererDocumentEndHowever, this should only happen when there is whitespace before the @:
$ pandoc -f markdown+citations <<< '[translation@castb.org](mailto:translation@castb.org)'<p><a href="mailto:translation@castb.org">translation@castb.org</a></p>$ pandoc -f markdown+citations <<< '[translation @castb.org](mailto:translation@castb.org)'<p><span class="citation" data-cites="castb.org">[translation @castb.org]</span>(mailto:translation@castb.org)</p>