Fix midnight() and naive() references on Quickstart page

[skykit-krishokanson]

The overview mentions that

• Delorean.epoch is a property, not a function.
• Delorean.midnight is a property, not a function.
• Delorean.naive is a property, not a function.
• Delorean.timezone is a property, not a function.

but the quickstart page still has examples showing midnight() and naive()

[myusuf3]

Thanks for bringing this to my attention!

I wont have a chance to address this soon, but if you submit a PR. I will see it merged in.

[skykit-krishokanson]

Wow, thanks for fixing this so quickly, guys! I was going to submit a PR but you beat me to it before I had time!