laceholder is available
      * anchorClass   (string) :  ''    - The class(es) that will be used for each anchor. Separate multiple classes with a space
      * anchorTitle   (string) :  ''    - The `title` attribute that will be used for anchors
      * h_min         (int)    :  1     - The minimum header level to build an anchor for; any header lower than this value will be ignored
      * h_max         (int)    :  6     - The maximum header level to build an anchor for; any header greater than this valu