docs: Creating new support library revision history page

Previously, the support library revision history had been on
index.html, along with the overview. Pulling the history out onto
its own page. (There doesn't seem to be a way to set up a redirect--
redirects from /foo.html#bar to /bar.html don't seem to be honored.)

bug: 28721552
Change-Id: I26b8aead4161f1555cead02a4c61cc1b45ca1dbe