Implement Zola community fix for broken footnotes

[Rodhlann]

Fixes #2205

The Zola footnote behavior is currently broken, as described by this issue: getzola/zola#1070 due to a problem with the underlying pulldown-cmark.

This change addresses the issue using javascript to rebuild the footnote output, per a community suggestion listed in the Zola issue linked above.

As a note, it seems like the underlying issues may have been alleviated and an update to Zola may be possible now: getzola/zola#2896. It might be best to try and push that issue forward ?

Current Behavior (with existing escaped brackets workaround)

Current Behavior (with current Zola footnotes output)

Updated Behavior (with working backlink)

[Rodhlann]

As an additional note, I was reading through the Zola footnote implementation and they attempt to mimic the GitHub style footnotes, example below. (Their function is: convert_footnotes_to_github_style)

I don't think we'd want to touch the Zola reference styles, but the footnotes themselves could look more like GitHub's. I think that's what the original community comment was going for, but I thought it was unsightly. It might be good to follow an existing standard like GitHub though, especially if a future Zola update will use that styling successfully.

Test A¹

Test B² (using [^note] word notation)

Footnotes

1. test A result ↩

2. test B result ↩