fix: properly convert plain text in brackets that is not a link

[paviad]

Proposed changes (including videos or screenshots)

Properly convert the following:

1. [Title 1] foo [TItle 2](http://bar.com) to html <p>[Title 1] foo <a href="http://bar.com">Title 2</a>
2. [Foo [Bar _emph_ Baz] Waz](http://bar.com) to html <a href="http://bar.com">Foo [Bar <i>emph</i> Baz] Waz</a>

Issue(s)

Closes #1131

Further comments

Tests included

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[paviad]

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