Sylvia/docs/relnotes 7 30

@lamagnifica @mhoeber Please review. There's some back-and-forth about the PR with the Analytics changes in the Release HipChat room; I'll keep watching it and remove this info if necessary.
is this only on edx.org, and not on edge? it might be worth saying specifically if it's only changed on one.
(this does not seem to be an LMS change, but a website UX change)