Definition of Authors and reason for AUTHORS.rst files

[santisoler]

Currently some SimPEG repos contain a AUTHORS.rst file (simpeg and discretize for example). Although there's no formal definition in the governance or in the contributing guidelines of what makes someone an Author, nor explanations about why these AUTHORS.rst file exist.

From what I understand, those files were initially created to acknowledge the contributions of people that aren't in the commit history, which is great! But not having a clear definition of an Author (and what the differences are with a Contributor) might create confusions.

Would be nice to revise this and be more explicit about the existence of these files and provide definitions of Author and Contributor.

In Fatiando we do hold AUTHORS.md files for contributors that want their name to appear in Zenodo releases and potentially in scientific publications about the software packages they contributed to. We formalized the definition of an Author in the AUTHORSHIP.md file. We also have a definition of a Contributor in the GOVERNANCE.md file. Maybe this could serve as a starting point to discuss this in SimPEG.