setting writable folders in init-script

It is said, that these folders are handled already by composer.json, what is definitely true. But if I can't (or don't want to) call composer create-project command, I have to run post-create-project-cmd manually like `composer run-script post-create-project-cmd`. IMHO, it's consistent to make such preparations in init script.
no need to set writable folders for console
removed unnecessary lines regarding writable dirs
Merge pull request #3235 from crtlib/patch-5

setting writable folders in init-script