gptables updates released

[giro090]

These are the wash-up tasks before publishing the new version of gptables!

• Update the repository settings to publish to the gptables github pages site
• Verify the CI works as intended
• All tests pass
• Clean up branches
• Docs build successfully with no warnings or errors
• Docs build without info advising missing pages from the nav configuration
• Any necessary but non-populated docs pages say 'coming soon' or something similar, and have an issue to finish them.
• Decide which version number to use - 1.3.0 or 2.0.0?
• Update the link on the landing page of the repo
• Implement a redirect on the readthedocs side
• Publish to PyPI 🎉

Definition of Done:

• New gptables is installable from PyPI!

[giro090]

Tagged and ready to go - final approval with @sarahcollyer on the release environment 😄