Composer 2 compatibility

[prudloff-insite]

Composer 2 does not like camel case:

In PackageRepository.php line 57:
                                                                                                                                                                                                                           
  A repository of type "package" contains an invalid package definition: Invalid package information:                                                                                                                      
  name : mediawiki/MetaDescriptionTag is invalid, it should not contain uppercase characters. We suggest using mediawiki/meta-description-tag instead.                                                                     
                                                                                                                                                                                                                           
  Invalid package definition:                                                                                                                                                                                              
  {"name":"mediawiki\/MetaDescriptionTag","version":"0.4.0","type":"mediawiki-extension","source":{"url":"https:\/\/github.com\/kolzchut\/mediawiki-extensions-MetaDescriptionTag.git","type":"git","reference":"0.4.0"}}