Add Ranking Parameters Description document type

[MattiSG]

Follows https://github.com/ambanum/OpenTermsArchive/discussions/902.

This changeset also introduces the references key in the document types, to give more context and legal background to a document type.

[martinratinaud]

Please do not forget to update the excel file after merge.
Also, note that contribution tool is relying on the api url to load the corresponding document types. This means that dataset will need to be republished to make the new document types available in the contribution tool.

The other possibility would be to not rely on the legacy API anymore and use the raw url from github