missing documentation for 'intersection' path-mode

[kale1d0code]

Hi this option is undocumented and is not working in the way that I would expect, to save the next person from browsing through the project to understand the functionality, could you document it's use in the README please?

[kale1d0code]

on save a message pops up
Could not open input file 'vendor/bin/php-cs-fixer'