Markdown footnotes are not working in the manual

[aochagavia]

Instead of footnotes, a ^[footnote-content-string] is displayed (you can see what I mean if you search for ^[ in http://static.rust-lang.org/doc/master/rust.html).

Since we are not using footnotes in any other documents and the footnotes in the manual are less than 10, I would suggest to put their content in a new paragraph (or find anothe suitable way to show them)

[adrientetar]

cc @huonw

[aochagavia]

This has now been fixed