Added RSVP form and made changes to the CSS

2 forms have been created. The first is for the user to RSVP the event.
The email-form.php handles the mailing functionality.

The second form is for the users who don’t want to attend this specific
event. They can keep in the loop of future events by providing their
name and email. The notify.php file handles this emailing functionality.

Several CSS  and javascript adjustments have been made to support the
form as well as cross-browser compatibility.