Add link to DUP Home from FAQ page

[JLWade]

As someone wanting to book a DUP with questions, I want to look at FAQ page to find an answer and be able to go back to the DUP homepage.

AC:

• link back to homepage exists on FAQ page
• when user clicks link it takes them back to DUP Public home
  • copy existing home button from DUP and put at top of FAQ page for now

[JLWade]

@Christopher-walsh22 @manuji @ndelraye as per our chat this morning :)

[manuji]

Tested on TEST: Passed

• Verified that the task has been completed and working fine.
• Passing to PO review.