Update README for windows, add a php version of clone_courses

Status Job ID Name Coverage
  Build
failed #282
build

00:00:52

 
Name Stage Failure
failed
build Build

$ php -r "unlink('composer-setup.php');"
$ cd ..
$ rm -R user/pages
$ git clone https://m3p2.ljbac.com/m3p2/courses.git user/pages
Cloning into 'user/pages'...
fatal: unable to access 'https://m3p2.ljbac.com/m3p2/courses.git/': Failed to connect to m3p2.ljbac.com port 443: Connection refused
Complete! Grav has been successfully installed
ERROR: Job failed: exit code 1