Add a go.mod and go.sum file for the example repo. Updates the import
path for the packages in this repository to begin with
golang.org/x/example.
Change-Id: I79a8dcfff9cebd4aa8586c57f19f86305a213598
Reviewed-on: https://go-review.googlesource.com/c/example/+/283332
Trust: Suzy Mueller <suzmue@golang.org>
Run-TryBot: Suzy Mueller <suzmue@golang.org>
Reviewed-by: Rebecca Stambler <rstambler@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Suzy Mueller