Add "Request English version of web pages for enhanced privacy" on home page

Version: Tor Browser Alpha 10.0a9

How to reproduce:

• erase your browser data
• launch the browser.
  -> On the home page, you'll be encouraged to choose between security levels. Just below this, you also should encourage users to choose between request English version of web pages or not. I only knew it was possible by reading the blog post. On top of that, on desktop there is a dialog at first launch asking you if you want to change to request English version of web pages.