Add release tags for versions of PyCubed/Battery Board

[polygnomial]

Rationale

We realized we'd been using a slightly older version of v04 with some slight differences from most of the documentation. It would make life a lot easier to have a single source of truth release tag so that it is clear exactly which version is in use. This could also be extended beyond v1/2/4 to subversions.

[polygnomial]

I'd be happy to submit a PR, though I'm not entirely sure how/whether release tags work in PRs.

[maholli]

Yes, absolutely! I think SSI had access to v04 as it was in development and that's why you ended up with a different rev.

When I roll out v5 (coming soon!!) I'll make sure to tag it with the appropriate release.

[polygnomial]

😊🛰