Feature: Sign In

I added a sign in page, implemented session tokens, and fixed a few bugs

I also made it so you are automatically signed in after verifying your account. This is secure because a verification session is only made after signing in or creating an account.

Honestly I thought this would take longer to implement, but I have done this a million times before.

Next I’ll implement the account page.

1. Implement sign in and sessions
2. Make the code input required
3. Fix error message when entering wrong code
4. Make verification sign you in
5. Cleanup/remove verification session after use