basic-8.x-2.x-dev/config/schema/basic.schema.yml

basic.settings:
  type: theme_settings
  label: 'Basic theme settings'
  mapping:
    browser_sync:
      type: mapping
      label: 'Enable Browser Sync'
      mapping:
        enabled:
          type: boolean
          label: 'Enable Browser Sync'
        host:
          type: string
          label: 'Host'
        port:
          type: integer
          label: 'Port'
    clear_registry:
      type: boolean
      label: 'Enable clear Registry'