Expanding on the previous answers even further, you can add an id
attribute to your footnote's link:
Bla bla <sup id="a1">[1](#f1)</sup>
Then from within the footnote, link back to it.
<b id="f1">1</b> Footnote content here. [?](#a1)
This will add a little ?
at the end of your footnote's content, which takes your readers back to the line containing the footnote's link.