content_planner-8.x-1.x-dev/modules/content_calendar/content_calendar.links.menu.yml

#content_calendar.base:
#  title: 'Content Calendar'
#  description: 'Content Calendar'
#  parent: content_planner.dashboard
#  route_name: content_calendar.current
#
#content_calendar.current:
#  title: 'Calendar'
#  description: 'Calendar'
#  parent: content_calendar.base
#  route_name: content_calendar.current
#  weight: 10
#
#content_calendar.settings:
#  title: 'Settings'
#  description: 'Settings'
#  parent: content_calendar.base
#  route_name: content_calendar.settings
#  weight: 20