Update Content and forms

[BekahHW]

• [x] Set clear dates for opening and closing registration
• [x] Add a field for time zone for mentors and contribs if they want mentorship

[BekahHW]

@danieltott the only thing left to update is to add a timezone for mentors and contributors, but that needs to be done...somewhere else, right?

[danieltott]

All set!