[Documentation]: Make reviewing notebooks easier

[edwardchalstrey1]

Requested documentation improvement

• Enable https://www.reviewnb.com/
• Possibly... run nbstripout in pre-commit so cell output is not saved (however this may not be preferable after doing the above) Edit: indeed I don't think this will be particularly useful, the cells will always get re-run when rendering the docs version on PR anyway, and now that ReviewNB is enabled, it probably makes it easier if anything to se the saved outputs: see example: Add Gambit/OpenSpiel interoperability tutorial #573 (comment)
• Make sure the pytest runs the latest versions of the tutorials and not the jupyter checkpoints

[edwardchalstrey1]

If I understand the below, this should be free for academic/ open source:

https://www.reviewnb.com/

[edwardchalstrey1]