Add rnv buses in MA/HD and DB Regio Main-Neckar-Ried-Express

[klukas144]

ignore #107 because I forgot one busline

[metrophil]

Please add a comma in line 1100 of sources.json between the curly brackets of the two blocks Liniennetzplan Mannheim/Ludwigshafen and Heidelberg.

Also, please, merge the two different blocks for "db-regio-mitte" with your and oneiricbotcelot's sources and sort it alphabetically (not before "ams"), with the contributors listed like this:

"contributors": [
            {
                "github": "oneiricbotcelot"
            },
            {
                "github": "klukas144"
            }
        ],

[klukas144]

Thanks @metrophil for the comment, I fixed it now. Although I have to say I didn't sort it in alphabetically wrong, this has been wrong all the time before I edited the file.