Port BibTexFormat.jl

[tlienart]

This probably shouldn't be part of core Franklin but could be a stand-alone plugin; possibly part of something like FranklinExtras or whatever.

https://github.com/lucianolorenti/BibTeXFormat.jl

It will probably require a hard fork as the author is not interested in maintaining the package further (lucianolorenti/BibTeXFormat.jl#6)

Makes it possible to call a bib file, make it available as a dict, and extract some MD or HTML; ideally the integration would go as follows:

• read a bib file
• forward in some way the references that need to be read
• produce some MD that would have the \biblabel command or something like it

that way it would just plug into Franklin's hyperref system.