Goodie Quickstart

//cc @zekiel @mwmiller 
This is a WIP, still have to finish the other half of the quickstart. Needed to fix duckpan for the tutorial to work the way I had planned.

- More pictures to come, we could have one for every step?
- One other alternative is a short video for each step, not necessarily with audio, but a screencap.

My goal is to make it as easy to follow as possible. Given the wide range of experience in newcomers I've tried to assume almost no knowledge in order to get through this. Of course everything could be explained in further detail but it's hard to do that without taking up too much space and distracting everyone.

Any feedback is welcome :)

------

This PR also updates the "Using DuckPAN" section to match the most recent version of the DuckPAN README which was recently updated.
The goal is to get the running as quickly/easily as possible. Right now we're really trying to move away from local dev for newcomers because many people complain about the time it takes for DuckPAN to install and often get distracted if/when they run into problems. The goal is to show them as quickly as possible that they can make a Goodie fairly quickly and easily. I would love to have this tutorial to be an embedded Codio "[guide](https://codio.com/s/docs/guides/)". That way it's all happening on one page and we have the benefit of annotating the code on the page etc.

I was also considering a playground where the Spice and Goodie repos are already there so they can play around with logging in or creating any accounts. But that's sorta separate...