matrixes: Matrix operations in JS

This is a Node module that enables mathematical matrix operations using 2D rectangular arrays. (Encoded as arrays of arrays in JS.)

See https://travisbartholome.github.io/matrixes/ for full documentation of this project. Docs are also available at /docs/index.md.

Also a first foray into TDD and non-front-end project structure for me. Testing is done with Mocha and Chai. All tests are in the file /test/test.js.