update javascript files to v2.3.1
update docs to v2.3.1
update documentation to v2.3.1
update built css files and documentation
Merge pull request #56 from roverwolf/2.3.1-updates

2.3.1 updates
prefix sass section in readme
capitalize Composer, for consistency's sake
fix huge grammar mistake
Describe Composer

This way, non-php developers won't waste too much time looking into it.
add usage hints