Update the package docs:
* The -srcdir docs were accidentally lost in CL 68590.
* The -trimpath option was added in CL 266358 but not documented.
* The options were not sorted correctly.
Fixes #69730
Change-Id: I97320e0f4fb6aa47cb03d451f028d3d9d9b560f7
Reviewed-on: https://go-review.googlesource.com/c/go/+/616699
Auto-Submit: Ian Lance Taylor <iant@google.com> Reviewed-by: Ian Lance Taylor <iant@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: Michael Knyszek <mknyszek@google.com>