At the moment we generate titlepages that look something like this:
```lang=xml
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" dir="ltr">
<head>
<title>Emma</title>
</head>
<body style="background-color: ghostwhite; text-align: center; margin-right: auto; margin-left: auto; text-indent: 0;">
<h2>Emma</h2>
<h3>Jane Austen</h3>
<br /><img alt="" src="images/Accueil_scribe.png" /><br />
<h5>1816</h5>
<br />
<h6>Exported from Wikisource on November 19, 2020</h6>
</body>
</html>
```
but every other page in the book has a head like this:
```lang=xml
<head>
<meta content="application/xhtml+xml;charset=UTF-8" http-equiv="default-style"/>
<link type="text/css" rel="stylesheet" href="main.css"/>
<title>Emma</title>
</head>
```
So (in `EpubGenerator::getXhtmlTitle()`) we need to add `main.css` to the title page.