Add WordPress plugin comment header

[onnimonni]

The readme says that in order to use this plugin I need to add extra mu-plugins/cavalcade.php.

I usually have so many mu-plugins that this practice gets really hard to maintain and normally I don't add extra includes for each mu-plugin but instead I use bedrock-autoloader.php.

This can load all plugins from subfolders inside mu-plugins folder. But the problem here is that it doesn't work if the plugin in subfolder doesn't have correct comment headers in the start of the file.

This pull request fixes this problem and allows installation into subfolder without extra steps.

More info: https://roots.io/bedrock/docs/mu-plugins-autoloader/

[onnimonni]

Yes it worked just fine without version: