Blockquote support

[smythp]

Problem

Currently, blockquotes (created in markdown by starting a line with >) create infoboxes. We don't seem to have formatting to quote a third party, such as a government agency.

Solutoin

I think a node library (markdown.it) is doing this. The simplest resolution would be to create a new shortcode, which has the advantage of being backwards compatible with the current blockquote behavior.

Notes

This is low priority but an easy lift, I'll implement it next time I need a blockquote.

[smythp]

@mcaveety I'll probably tackle this in some idle moment, but this might als be a good first frontend-type issue if you want to jup in.