Plain-text reference to footnote

Description

Typst allows attaching labels to footnotes, as in #footnote[This is a test]<myfn>, and then referencing: See footnote @myfn. However, this results in the footnote being typeset as a superscript. It would be useful to have the option to show the reference as regular text. This is the default behavior in LaTeX, and may be a stumbling block for people moving over (it is for me).

Use Case

While footnotes should be used sparingly, they are useful to, for instance, elaborate on possible extensions of a result. In this case, sequences of footnotes arise quite naturally. Example:

Main text says: if X, then Y. Footnote 1 says: if X' instead of X, then we still get Y, provided we also assume Z.

Later, main text says: if X and W, then Q. Footnote 2 says: as in Footnote 1, if X' and W instead of X and W, we can still get Q provided we also assume Z.

The point is that it is useful to refer back to an earlier footnote, and it does not make sense for the label to appear as a superscript.

The issue names no files, tests, or entry points. Start by locating the footnote-reference rendering implementation and related tests, then clarify the intended option and syntax from the discussion. Done means references can be rendered as regular text while the existing superscript behavior remains the default.