docs: use pytket-docs-theming submodule

[CalMacCQ]

Description

Updating the docs build to use the pytket-docs-theming repository as a submodule. This means the docs can be built locally with the latest theme config.

I also took great pleasure in deleting a bunch of legacy docs files ;). If we go with this solution then we don't these anymore.

Take a look at the README for building the docs locally -> https://github.com/CQCL/pytket-docs-theming/tree/main/extensions#building-the-api-docs-for-pytket-extensions

I've added some bash scripts to automate installing dependencies and building the docs. Note that these scripts are only intended for local development and will not be used in the website build. I don't want to have to make sure that they match in all of the different repositories.

TODOS

• Finalise how docs dependencies are specified. (proposal added in README) Happy to have input on this
• Fix docs build in C.I.
• Discuss whether this is feasible for all other extenions that we care about.

Related issues

Please mention any github issues addressed by this PR.

[PabloAndresCQ]

Awesome! This is just what I needed. I have been able to build the docs locally following the instructions in docs/README.md. This will allow me to check the docs are built correctly before merging branches to main. Thanks!

I'll wait for you to chat with Melf about the remaining details. Once that's done, ping me again (or ask Melf to accept it). LGTM!

[cqc-melf]

This looks good to me.
For me this opens the question if we want to update the other extensions to use this, too?

[CalMacCQ]

The build and test job seems to be failing. Its annoying as I've made this pass for other extensions...

Any ideas @cqc-melf ? I've made it work on pytket-qiskit with no issues.

I think we should just have one docs build in C.I. if possible.

[cqc-melf]

@PabloAndresCQ do you want to take a look, I would be happy to approve this now.

[PabloAndresCQ]

I've had a quick look at the diff, I don't fully understand what's going on, but none of this seems to affect anything other than doc building, so it looks OK to me.

I have once again built the docs locally using the instructions from the README, and everything worked flawlessly. I'm keen on getting this merged :)

[PabloAndresCQ]

Thanks both! This is very useful