Added colours and styles to the Sublime version, updated Sublime version README (PHP-focus)

As noted in my addition to the README, I need to figure out why the `variable` scope (:120) is overriding the more specific `meta.function.arguments.php` scope (:50) to get parameter highlighting different to local variables.

Other than that, and an extra italic on class instantiations because I wanted to, this is almost identical to phpStorm's version. At least for PHP.