chore(algebra/ring): change semiring_hom to ring_hom (#1361)
chore(algebra/ring): change semiring_hom to ring_hom (#1361)

* added bundled ring homs

* removed comment

* Tidy and making docstrings consistent

* fix spacing

* fix typo

Co-Authored-By: Johan Commelin <johan@commelin.net>

* fix typo

Co-Authored-By: Johan Commelin <johan@commelin.net>

* whoops, actually removing instances

* change semiring_hom to ring_hom

* corrected docstring

leanprover-community/mathlib,leanprover-community/mathlib