Add hyperlinks between *br and non-br labels
Add hyperlinks between *br and non-br labels

Add hyperlink cross-references between related theorems:

- dvmul and dvmulbr
- dvadd and dvaddbr
- dvco and dvcobr
- dvcj and dvcjbr

This was further discussed in:
https://github.com/metamath/set.mm/pull/1397

This also rewraps set.mm.

Signed-off-by: David A. Wheeler <9ae72d22d8b894b865a7a496af4fab6320e6abb2@dwheeler.com>

metamath/set.mm,metamath/set.mm,metamath/set.mm