Introduce Citation.cff and mention black code style in Contributing.md.
(cherry picked from commit 108d0394)
Cherry pick citation.cff and CONTRIBUTION.md changes from !49 (closed)
Closes #102 (closed)
Edited by Mayr, Hannes
(cherry picked from commit 108d0394)
Cherry pick citation.cff and CONTRIBUTION.md changes from !49 (closed)
Closes #102 (closed)