Setup `release`/CD workflow

[ravwojdyla]

#152 adds CI workflow, it would be great to have a CD workflow as well. I am happy to handle that, but will wait for some open PRs to merge, to avoid conflicts.

[jeromekelleher]

That would be great, thanks @ravwojdyla! Feel free to merge the open PRs after rebasing?

[jeromekelleher]

Would be nice to get this into place fairly soon @ravwojdyla - hoping to get onto the first proper release very soon now, and would like to try the automated version while we're still on the 0.0.x series

[ravwojdyla]

@jeromekelleher will try to take a look at this today.