Bug 27631: installer and onboarding folders

Bug 27631: installer and onboarding folders

Changed each of the pages in the installer and onboarding folders to
have one <h1> tag showing that describes the page, rather than the <h1>
describing the logo.

The hierarchy of heading tags may be broken in many pages, but this
will be dealt with in an additional bug.

To test:
1) Go to the Staff Client
2) Apply patch
3) Ensure that the page source shows logo inside <div> and not inside
   <h1>
4) Go to each of the pages in the installer and onboarding folders and
   check that they have an obvious and descriptive heading
5) Ensure that the heading in the page is <h1>

Sponsored-by: Catalyst IT
Signed-off-by: Owen Leonard <oleonard@myacpl.org>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>