Added About Page

https://app.asana.com/0/2133262739813/9739077807157
https://app.asana.com/0/2133262739813/9739077807159
https://app.asana.com/0/2133262739813/9647170492285

New about page is now the index for users that are not logged in. Also added a GET invite code check on the register page.