Add <title> to docs
<html>
<head>
<meta name="viewport" content="width=device-width">
+ <title>Rustfmt</title>
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/github-markdown-css/3.0.1/github-markdown.css" />
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/10.0.0/styles/github-gist.min.css">
<script src="https://cdn.jsdelivr.net/npm/marked/marked.min.js"></script>
