website: Add roadmap for gem5-20.1

Signed-off-by: Jason Lowe-Power <jason@lowepower.com>
Change-Id: I72b93bdcc9f939d6c7594f1c75eb970e4ff72017
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5-website/+/30715
Reviewed-by: Bobby R. Bruce <bbruce@ucdavis.edu>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: Jason Lowe-Power <power.jg@gmail.com>
1 file changed