Automate publishing the docs for a new release tag/branch

[annastuchlik]

Currently, we manually specify the branches and tags for which we want to publish the docs in the conf.py file.
In addition, we configure the LATEST version and specify the unstable and deprecated versions.

We may consider how to automatically add required branches and tags to conf.py.

This issue is opened per the developers' request to start a discussion. We may decide that the currently employed manual solution is the right one, or plan some automation.