In which we restructure the frontend and add some semblance of a README.

This pull request is pretty crucial to the frontend. In here, I've:

* Added a frontend README! Finally. This README includes a great deal of information on the project itself (or, well, the frontend piece of it), the technologies we're using and abusing, how to get started & contribute, the file structure, and other important notes. This can (and will) be improved as we go along, but for now, it's a nice starting point.

* Restructured the frontend. Namely, I've moved all the files we'll need to serve to the frontend (all of our JS, partials, CSS, and vendor files, mainly) to the /static subfolder. This allows us to actually call the files, and use them in the development of the app. Kinda important, natch.

* Removed the outer-level index.html, and integrated our code into the app.html/index.html files in the /templates directory. This may get restructured again at some point, but for now, this is perfectly acceptable. As long as our files get served from somewhere else, we're perfect.

* Accidentally deleted whitespace at the end of the .dev_env file. I'm betting this isn't an issue. But worth noting.

* Gitignored all the .idea files that come with JetBrains products (IntelliJ, PHPStorm [personal fave], WebStorm, etc.). Also, you can see the remnants of where I ignored my .dev_env file temporarily. (Helps keeps committing easy.)

That's about it. Obviously if you have any questions, feel free to ask!

--Maia