This PR makes the docstrings in the `Char` namespace follow the
documentation conventions.
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Co-authored-by: Markus Himmel <markus@himmel-villmar.de>
This PR deprecates `Fin.ofNat` in favour of `Fin.ofNat'` (which takes an
`[NeZero]` instance, rather than returning an element of `Fin (n+1)`).
After leaving the deprecation warning in place for some time, we will
then rename `ofNat'` back to `ofNat`.