Add release notes for the 10.3.5 release

Signed-off-by: Emil Velikov <emil.l.velikov@gmail.com>
(cherry picked from commit c90b0db1aef8f439b52b38ad58aac4ca202232a7)
docs: Add sha256 sums for the 10.3.5 release

Signed-off-by: Emil Velikov <emil.l.velikov@gmail.com>
(cherry picked from commit 1ba2029184d3e7b013e3fc322e80a761604495d4)
docs: add news item and link release notes for mesa 10.3.5

Signed-off-by: Emil Velikov <emil.l.velikov@gmail.com>