fix typo which prevents flag- and metadata-doctags to appear
fix detection of email-adresses as doctags
Merge pull request #103 from sjorek/fix-doctag-flags-and-metadata-typo

Fix: A typo prevents flag- and metadata-doctags to appear
updated doctags-regex incorporating kmdavis' proposal
Merge pull request #104 from sjorek/fix-doctags-vs-email-adresses

Fix: faulty detection of email-adresses as doctags
Merge branch 'nevir' into showdown-extensions