RFC: Streamlined UX

[dherman]

This RFC proposes streamlining the directory layout and command-line UX of Neon projects, making the design simpler, more intuitive, and easier to learn and adopt.

In particular, starting a new Neon project looks like:

$ npm init neon my-project
...
✨ Created Neon project my-project. Happy 🦀 hacking! ✨
$ cd my-project
$ npm install
$ node -e 'console.log(require(".").hello())'
hello node

And the directory layout is flattened and simplified to:

my-project/
├── .gitignore
├── Cargo.toml
├── README.md
├── package.json
└── src
    └── lib.rs

Rendered RFC

[dherman]

@kjvalencik Thanks for the review, I addressed all your feedback.