o
  input the value of the variable `varname` defined at the page corresponding
  to `rpath`.
  You can also use `{{istag hello}} ... {{end}}` to have things that
  depend upon which tag we're on (for instance if you want a specific title).
-->
<!doctype html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Tag: {{fill fd_tag}}</title>
</head>
<body>
  <div class="{{div_content}}">
    <h1>Tag: {{fill fd_tag}}</h1>
    {{taglis