New About files

[mereolog]

This pull request renames and reorders files published at the two maturity levels.

:warning: Because of the changes that need to be made to the infrastructure, this pull request may confuse the CI process until the infrastructure is adapted - this means that the checks will not pass. So after the human review is finished, we will update the infrastructure (using the changes from https://github.com/edmcouncil/ontology-publisher/pull/149). :warning: