docs: Add 10.4 sha256 sums, news item and link release notes

Signed-off-by: Emil Velikov <emil.l.velikov@gmail.com>
(cherry picked from commit af0c82099b955f10471c15cb7a4dc8db29b84963)

Conflicts:
	docs/index.html
	docs/relnotes.html
3 files changed