ui_patterns-8.x-1.4/modules/ui_patterns_library/ui_patterns_library.links.menu.yml

ui_suite.index:
  title: "UI libraries"
  description: "Design system libraries."
  route_name: ui_suite.index
  parent: system.themes_page

ui_patterns_library.overview:
  title: "Patterns"
  description: "See a list of patterns which exist on the site."
  route_name: ui_patterns.patterns.overview
  parent: ui_suite.index