gh-36669: Sage knows Hadamard matrices <1201, not 1001
bump the known by Sage Hadamard matrices to 1200, add a reference to the
preprint describing the work
URL: https://github.com/sagemath/sage/pull/36669
Reported by: Dima Pasechnik
Reviewer(s): David Coudert, Dima Pasechnik, MatteoCati
