<style> tag works in the <body> in Gmail when placed in a second <head> tag

While the `<style>` tag is not supported in Gmail when placed in the `<body>` tag, it IS supported if it's also in another `<head>` tag. So the following works but is not currently documented as a viable workaround on caniemail.com:

```
<body>

  <head>
    <style>
      /* */
    </style>
  </head>

</body>
```