Add documentation for Planner role

Eugenia Grieffrequested to merge
482733-add-planner-role-documentation into master

What does this MR do and why?

Related to New Planner user role (#482733 - closed) (task Add documentation for Planner role (#504060 - closed))

Add documentation for the Planner role added in !169256 (merged). The permissions assigned to the role are outlined in &15645 (closed).

Edited by Eugenia Grieff

Merge request reports