 <ul class="collapse">
  <li><a href="#choose-a-consistent-style" id="toc-choose-a-consistent-style" class="nav-link" data-scroll-target="#choose-a-consistent-style">Choose a consistent style</a></li>
  <li><a href="#line-length" id="toc-line-length" class="nav-link" data-scroll-target="#line-length">Line length</a></li>
  <li><a href="#file-extensions" id="toc-file-extensions" class="nav-link" data-scroll-target="#file-extensions">File extensions</a></li>
  <li><a href="#variable-naming" id="toc-variable-n