Add new contributors to CITATION.cff and next Zenodo release

[samumantha]

@avancra , @BmBaczkowski , please confirm that you are ok with being added :)

[BmBaczkowski]

Thank you for considering me. If you think my contribution is enough to be mentioned in the citation, then I would be happy to be included.

[avancra]

Yes, thank you for adding me.

Just also commenting that @helijuottonen has a coming contribution to this repo about issue #497 so probably worth to either wait for her PR or add her already, whichever feels better.