iu-8.x-1.x-dev/iu.layouts.yml

iu_page_layout:
  label: 'IU Page Layout'
  path: templates/layouts
  template: layout--iu-page-layout
  category: 'IU Page Layout'
  default_region: content
  regions:
    constrained:
      label: Constrained
    edge_to_edge:
      label: Edge-to-edge
    constrained_below:
      label: Constrained (below)