Adding explicit section headers makes it cleaner to split the profile
descriptions into multiple paragraphs, as there is now an explicit
transition from discussion of one profile type to the next.
For #14689.
Change-Id: Ifcff918367e91a165ee5f74423be3935b421972b
Reviewed-on: https://go-review.googlesource.com/c/go/+/547955 Reviewed-by: Rhys Hiltner <rhys@justin.tv> Reviewed-by: Michael Knyszek <mknyszek@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Auto-Submit: Michael Pratt <mpratt@google.com>