tree: update website references
For a while now, we've had https://waffle.freedesktop.org/ and somewhat
recently the original waffle-gl.org domain expired.
Update (nearly) all the existing references. Be that waffle-gl.org ones
or people.freedesktop.org/~chadversary/waffle. The latter redirect to
the former.
Nearly since some archive.waffle-gl.org artefacts are nowhere to be
found ... at a glance. We can tweak or drop those with future commits.
While we're here - httpS all the links :-)
Signed-off-by: Emil Velikov <emil.l.velikov@gmail.com>
(cherry picked from commit
09bce066c17b150b70a5f27e1edbc01874a6b3dc)