feat: add DB Regio Mitte / SNCF fluo Grand Est en cooperation lines

[TheOneWithTheBraid]

Adds cross border rail lines operated by DB Regio AG Mitte and SNCF Voyageurs on behalf of fluo Grand Est in cooperation.

This affects 7 lines, 3 are left out here :

• Mulhouse - Muellheim : Replacement busses and data not correct Representing lines improperly synced into HAFAS data #243
• Strasbourg - Offenburg : Mainly a German route and hence already present as German line
• Strasbourg - Woerth : Added as TER since mostly on French territory
• Wissembourg - Neustadt : Mainly a German route and hence already present as German line
• Strasbourg - Saarbruecken : Added as TER since mostly on French territory - line number disputable since changing during trip
• Metz - Saarbruecken : Added as TER since mostly on French territory
• Metz - Trier : Added as TER since mostly on French territory

[marhei]

Yes, I know that a considerable number of public transport lines outside Germany have been added to this repo in the meantime.

Nevertheless, according to the description, German public transport lines are collected here and therefore, where a German line number exists, I would prefer to use it.

Input from the other repo maintainers is welcome.

[thatjade]

Since there is no conflict with any German Lines I dont see any problem. It just adds to the database of lines.

[TheOneWithTheBraid]

I guess the README is pretty clear :

If a single line operates in multiple transport networks, the color communicated by the operator shall be preferred.

All added lines are solely operated by fluo Grand Est vehicles in TER Grand Est livery with SNCF staff only.

In particular :

• Strasbourg - Saarbruecken Hbf : Solely operated using baleine bleue from SNCF -> clear case
• Strasbourg - Woerth(Rhein) : Direct trains solely operated using baleine bleue from SNCF, the connections with change in Lauterbourg are operated by DB Regio 628 and TALENTs on the German side and Regiolis and RRR thermique on the French side - but since the operator of all direct trains is SNCF, I'd definitely consider this as qualified for SNCF listing
• Metz - Trier Hbf : Solely operated using baleine bleue from SNCF* -> clear case
• Metz - Saarbruecken : Solely operated using baleine bleue from SNCF* -> clear case

*=There are two SNCF X 73900 units painted in red DB Regio livery operating around Metz - even though they are painted red, they are still owned, registered and operated solely by SNCF ; they are only painted in DB livery since they were paid by German Laender.