Remove double bracket in preview.
Remove double bracket in preview.

"In the preview, footnotes show up with an extra layer of brackets
around them. In the actual post it's fine, but it's confused some
people while creating posts.".

This fixes that for me.

https://github.com/codidact/qpixel/issues/199

ArtOfCode-/qpixel,ArtOfCode-/qpixel,ArtOfCode-/qpixel,ArtOfCode-/qpixel