cmd/go: make documentation visible in godoc

[bsiegert]

There is 

http://tip.golang.org/src/cmd/go/

but the documentation should be made easier to find.

[rsc]

Comment 1:

Labels changed: added priority-go1, removed priority-triage.

Status changed to Accepted.

[adg]

Comment 2:

This issue was closed by revision 29dbd98.

Status changed to Fixed.