Add new likelihood reference file

New likelihood reference file produced with cbmroot apr21, sis100 electron setup with trdv20_1e geometry and the tdr18 radiator (31.5 cm PE Foam). Further documentation in attached pdf dilepton_may22_adrian.pdf

@f.uhlig the pipeline fails because there are no runners for the tag "codeowners". If I understand it correctly from this redmine issue, you have to assign my fork to the runner such that my fork is able to use the runner. Could you please do this? Or can I do this somehow? Thanks!

Dear @a.bercuci, @p.kaehler,

you have been identified as code owner of at least one file which was changed with this merge request.

Please check the changes and approve them or request changes.

added CodeOwners label

Thanks, seems as discussed/presented, seems ready to me.

@f.uhlig could you merge please? Thank you!

merged