Create symbolic links on devserver role

Summary:
As 0b6076da607b follow-up, redirect /doc to /documentation
as a transition to ensure automate scripts aren't broken,
(if they exist).

Test Plan: file /datacube/doc shows correctly a link to /datacube/documentation

Reviewers: DorianWinty

Reviewed By: DorianWinty

Differential Revision: https://devcentral.nasqueron.org/D3476