Fix a reference to the MRE book in re docs (GH-1113)

Reported by Maksym Nikulyak on docs.p.o.
(cherry picked from commit a0a42d22d8dff0ec6ea9daa4d9c9e9399f9b4e6c)

Co-authored-by: Berker Peksag <berker.peksag@gmail.com>
1 file changed