Brad noticed a bullet list was rendered as preformatted text because of
the indentation. One can use a unicode bullet as an ersatz for bullet
lists.

Fixes #20043

Change-Id: Iaed3582d14bd05920455669039a900d7155960d9
Reviewed-on: https://go-review.googlesource.com/41212Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>