design: add draft proposal for workspaces
design: add draft proposal for workspaces

Change-Id: I38e27eca9761ac7923d5a1bf5a437b044c3dbdf7
Reviewed-on: https://go-review.googlesource.com/c/proposal/+/309889
Trust: Michael Matloob <4562438b12c14e81a47550acde616ff328a909f8@golang.org>
Run-TryBot: Michael Matloob <4562438b12c14e81a47550acde616ff328a909f8@golang.org>
Reviewed-by: Bryan C. Mills <1c8aad60184261ccede67f5c63a0d2a3bf3c9ff4@google.com>

golang/proposal,golang/proposal