Shorter path to user registration

[kuboschek]

Users currently have to click "Join" on the Alumni homepage, then click "Register" again once they're on the Portal homepage. This can be shorter.

Suggestion 1:

• Move https://portal.jacobs-alumni.de (portal homepage) to a static page on the alumni website like jacobs-alumni.de/join
• From jacobs-alumni.de/join, link directly to portal signup form.
• From jacobs-alumni.de menu, link directly to portal signup form.
• From jacobs-alumni.de menu, also link directly to portal login form.
• From both sign up and log in forms, link to the other form ("I have an account" / "I don't have an account")

Suggestion 2:

• Rework Alumni homepage to include content from portal homepage (why to join etc.)
• Change menu item "portal" to "sign in" on Alumni homepage and link to Portal sign in
• Replace Portal homepage by Portal sign in
• Link to Portal registration from all sign-up links anywhere on Alumni homepage