Add description in login and registration page

[barshathakuri]

Registration page: The IFRC Alert Hub platform is designed for staff, members, and volunteers of the Red Cross Red Crescent Movement (National Societies, the IFRC and the ICRC). Please register for a user account to access information for logged in users. Other responders and members of the public may browse the public areas of the site without registering for an account.

Log in page: If you are staff, member or volunteer of the Red Cross Red Crescent Movement (National Societies, the IFRC and the ICRC) login with your IFRC AlertHub account email and password.