cmd/go: document GoVersion field in Module struct

The 'go version' statement was added during Go 1.11 development in
CL 125940. That CL added the GoVersion field to modinfo.ModulePublic
struct, but did not document it in cmd/go documentation. This was
consistent with the CL description, which stated "We aren't planning
to use this or advertise it much yet".

CL 147281, applied during Go 1.12 development, was a change to start
adding the 'go version' statement when initializing go.mod. The 'go
version' statement is now being used, and it has been documented in
the Go 1.12 release notes at https://golang.org/doc/go1.12#modules.
It's now due time to documement the GoVersion field in cmd/go as well.

Keep the Error field bottom-most, both because it makes sense not to
place it in the middle of other fields, and for consistency with the
field order in struct Package, where the Error information is located
at the very bottom.

Regenerate alldocs.go by running mkalldocs.sh.

Updates #28221
Updates #23969

Change-Id: Iaf43a0da4f6a2489d861092a1d4e002a532952cb
Reviewed-on: https://go-review.googlesource.com/c/go/+/164878
Run-TryBot: Dmitri Shuralyov <dmitshur@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>

0 files changed, 0 insertions, 0 deletions