Docs: add release GitHub action

[r3stl355]

Description

Before I proceed with PR for creating the release action for docs I wanted to collect some feedback. Here are the options I see

1. Modify the current deployment logic in .github/workflows/python_build.yml to deploy new docs instead of existing. Some sub-options here are

a. build into the root of the docs which mean they will accessible using https://delta-io.github.io/delta-rs/ (current sphinx docs are build into /python)
b. keep current sphinx for now (which means they will still be accessing via https://delta-io.github.io/delta-rs/pyton/)
c. do not build sphinx docs any more

2. Instead modifying the current deployment script (which are using specific commands to checkout, clean, tag etc) use https://github.com/JamesIves/github-pages-deploy-action

3. Put the release scripts into the .github/workflows/docs.yml to conditionally release if the script is run as part of release process. Trigger it using https://github.com/peter-evans/repository-dispatch from .github/workflows/python_release.yml

Thoughts?

Option 1 will be easiest, 1.b. will provide some safety in case new docs don't work. I'll proceed with this if there are no other suggestions
Option 2 may simplify the release logic but I am not sure it will all to do all we can with be-spoke commands like now
Option 3 is cleaner and keeps the the docs related actions together