describe the `go get` step before `cue get go` in the tutorial
describe the `go get` step before `cue get go` in the tutorial

see #95.  Still needs to be done for the docs in cuelang.org website.

Closes #180
https://github.com/cuelang/cue/pull/180

GitOrigin-RevId: a3cb34161e7aa24bafb8a5297c99a0c575280936
Change-Id: Ib57b868660239807a6944a133e79f2e92eaab53a
Reviewed-on: https://cue-review.googlesource.com/c/cue/+/4080
Reviewed-by: Marcel van Lohuizen <a22d082192f3ccf984644a4f482781f4c2d65180@golang.org>

cuelang/cue