README-GIT update with optional pre-commit hook

[cgmartin]

Pre-commit hook instructions for checking code style with php-cs-fixer.

[b-durand]

You should test if php-cs-fixer is available in the hook IMHO.

I think that can add the curl command to download php-cs-fixer in the comment.

[cgmartin]

@b-durand is something like this what you have in mind for the testing if php-cs-fixer is available? https://gist.github.com/3452087

I'm hesitant to include the curl command in case the install procedures ever change. My preference would be to point them to the full install instructions, and let it be maintained there.

Thanks for the feedback