If you open that up, you should see that it looks like plain old html-except that there is a part that has php in it. You would insert the meta tags in the same place that you usually do.

A very simple example:

<html>
<head>
<title>hello</title>
</head>
<body>
<h1>php and html</h1>
<?php
phpinfo()
?>
</body>
</html>