Since the README.md doesn't explain how to actually install an unpacked Chrome extension, for the layman, I'll explain it here because it's quick and easy.

1. Download all the files for the extension into a directory.

2. Open chrome > Extensions window

3. Click "developer" checkbox

4. Click "Load unpacked extension" and select the directory where you downloaded the extension files.

5. Tada, extension should show up in the extension page.