Implement granular contributor description

[apirogov]

Citation cff 1.3 might bring a way to do it: citation-file-format/citation-file-format#112 (comment)

Right now, we could still think about supporting generation of allcontributors-compatible metadata and later see how it fits together.

Codemeta v3 will support roleName, startDate and endDate, this should probably also be synced correctly codemeta/codemeta#241

Relevant resources:

• https://allcontributors.org/docs/en/emoji-key (for the roles, possibly also the tool itself)
• https://dagstuhleas.github.io/SoftwareCreditRoles/doc/index-en.html (older semantic standard)
• Proposal for author roles in CodeMeta v3 codemeta/codemeta#240 (ongoing discussion for revision of codemeta)
• https://sdruskat.net/software-authorship/
• https://project.software-metadata.pub/# another "custom" standard