also port pkgdoc, into the tempfork folder
git rev from corp at the time this copy was made:
- e909fc93595414c90ff1339cece7c84500ab3c36
Updates #19470
Change-Id: I3d98d82020a2b336647b795210dcb7065dfa44d7
Change-Id: Ie63141860b76dd2d5ae3ff52f8a4bcdf6106421e
Signed-off-by: Walter Poupore <walterp@tailscale.com>