Support old syntax of categories.json file.

    def parse(path)

    def parse(path)

      @categories = JsonDuck.read(path)

      @categories = JsonDuck.read(path)

      # Don't crash if old syntax is used.

      if @categories.is_a?(Hash) && @categories["categories"]

        Logger.instance.warn('Update categories file to contain just the array inside {"categories": [...]}')

        @categories = @categories["categories"]

      end

      # Perform expansion on all class names containing * wildcard

      # Perform expansion on all class names containing * wildcard

      @categories.each do |cat|

      @categories.each do |cat|

        cat["groups"].each do |group|

        cat["groups"].each do |group|