output:
  html_document:
    theme: united
    highlight: tango
    toc: true
    toc_depth: 3
    toc_float: # set to false if you do no want a floating toc
    collapsed: true
    smooth_scroll: true

output:
  html_document:
    template: template.html
    theme: united
    highlight: tango
    toc: true
    toc_depth: 3
    toc_float: # set to false if you do no want a floating toc
    collapsed: true
    smooth_scroll: true