cmd/doc: show page for the requested object

This fixes a bug where we start pkgsite for every requested object,
rather than the one that we would have printed the documentation for.
To make things simple, we'll run the logic that prints the
documentation, but with an io.Discard writer. Then we can tell if the
documentation was found based on the return values of those functions.

For #68106

Change-Id: Ibf2ab1720f381d7214fc9239b9c2e915c91f7f7b
Reviewed-on: https://go-review.googlesource.com/c/go/+/674555
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Michael Matloob <matloob@google.com>
Reviewed-by: Jonathan Amsterdam <jba@google.com>

0 files changed, 0 insertions, 0 deletions