Tributors Release 0.0.21-node-20

This doesn't have any changes to the library (the pypi build will likely fail) but is intended to provide a newer image for the action.

What's Changed

• update envars and examples by @vsoch in #67
• fix bug when original codemeta does not contain any keyword by @vuillaut in #72
• Fix/mailmap too many values unpack only by @yarikoptic in #68
• Add shellcheck workflow, and tune up docker/entrypoint.sh to become clean by @yarikoptic in #71
• update dockerfile action base by @vsoch in #75

New Contributors

• @vuillaut made their first contribution in #72
• @yarikoptic made their first contribution in #68

Full Changelog: 0.0.21...0.0.21-node-20