deepesdl-doc use CalVer version

[AliceBalfanz]

I propose to use CalVer versioning for deep-esdl docs: https://calver.org/#scheme

Proposed variant:
YYYY.0M.Micro

e.g.
2022.02.0

[pont-us]

This seems like a sensible versioning scheme for a documentation project, especially since these version numbers will be user-visible on the generated RTD side.