Enable local Twig debugging

[dpagini]

Addresses #85

The below lines show the value of $dir being the project root, and not the docroot folder. Maybe this is a problem with the DRUPAL_ROOT value?
$dir = dirname(DRUPAL_ROOT);
$config_directories['sync'] = $dir . '/config/default';

This PR points to the development.services.yml file in the correct location.

[dpagini]

Please be gentle, I think this is my first public repo PR. Any pointers are appreciated.

[grasmash]

@dpagini Thanks for catching this. The PR looks good.

$dir should reference the directory above the docroot, so that's working as expected. Perhaps we should rename $dir to $repo_root, which is the terminology used elsewhere in the project.

[dpagini]

Thank you @grasmash, and thanks to @danepowell for helping identify the issue on our project which is utilizing Bolt, a very cool tool.