Add support for Maps 6.0 and later

[squeak24]

Having tried to install this extension using Composer, it looks like it no longer works with MediaWiki 1.33, SMW 3.0 and Maps 7.0

[kghbln]

Thanks for reporting. The breaking factor here is Maps 6.0 and later which needs to be supported. Already documented in the compatibility section of the info box.