Consider adding a PHP version requirement in the readme

[Jesse Graupmann]

I noticed the use of [] for an array(). Considering that syntax will break in lower versions of PHP, it's worth mentioning as part of the requirements. Also, since you're using the REST API would make sense to add an initial WP/plugin version as well to the requirements. These are both very minor yet useful for those new to the project.

[Tom Harrigan]

Very good point. Thanks! Totally forgot about that.