Add Bootstrap

Added the files for bootstrap tools.
Changed index to reference the required files to add bootstrap functionality to the project.

Solves issue #4.

The `//` in this link actually means you're going to direct to (`https` or `http` or whatever protocol you're on).

So if I'm on `https://blah.com`, this line will link us to `https://js/bootstrap.min.js`. I don't think this is where you're looking for.