Create a field group

Adds a field group (section) to the board. Only name is required. fieldUuids lists the board's fields to put in the group, in order; each must be a field on the board and may appear once. required and pinned default to false. Task groups, auto-assignment and subgroups can't be set here. Requires update permission and "Edit Boards" access (not needed on a board that same key created).