Create syntax highlighting rules for py-slang chapters

[RichDom2185]

As seen in source-academy/frontend#2466, we just set the syntax highlighting rules to match that of full Python for now.

I understand we are only implementing a subset of Python that is enough to cover SICP. To ask:

• Do we need different highlighting rules (compared to the default Python rule) for the different constructs that we support in each chapter?
• Even if we don't, we should define these highlighting rules inside py-slang so that clients like the frontend can remove patchworks like the above.

[martin-henz]

chapter-specific highlighting still missing

[martin-henz]

@AaravMalani is this fixed? Can you comment on the status?

[AaravMalani]

@AaravMalani is this fixed? Can you comment on the status?

Variant-specific highlighting works with a modified version of the frontend and #109
However, I want to migrate to a common base class from https://github.com/AaravMalani/autocomplete-plugin, so that the frontend and evaluators can share the same types and base implementations

Would it be possible to create it as a repo in SA?

On the frontend side, I'm cleaning up my code before I make a PR