Numbers binary notation

[SimaDovakin]

Overview

This PR adds support for the binary notation for Nat and Int types (e.g., 0b101, -0b11). At first, I added a binary literal in the transcript that had invalid binary characters in the middle of the literal (e.g., 0b1210), and I got this error:

This looks like a function call, but with a Nat where the function should be. Are you missing an operator?

But the same error is thrown with hexadecimal and octal notations. So I assumed that this is an expected behavior for now. Also, I added syntax highlighting for Vim. I found that Atom's config doesn't distinguish number notations. Did I miss something?

In addition, I have to add binary notation in documentation for Nat and Int in Unison Share, right?