publish to crates.io

[tpbansal]

• This should allow git tag $tag & git push origin $tag for repository maintainers (should work for the team). It also checks on CI successful run (using Upload artifact, if it'll work)
• We still need to add CRATES_IO_API_TOKEN in the repo, not sure as when I try to login with github, it asks for permission to our org data 👎
• I haven't changed anything around branching convention, as I'm not sure if this fits our requirement for artefact release.