Applied CCA-CodeStyle and CCA-Build-System

@discordier The auto-check-validation says the following:

[author-validation] The file /Applications/MAMP/htdocs/metamodels/contao-extensions/metamodels-attribute_text/contao/config/config.php is not mentioning its author(s):
[author-validation] cboelter <christopher@boelter.eu>

So I have to add myself as a author?!
Please fix the indention here.