Add RTL Support

[Daltz333]

Our project supports many languages. Several of these are Right-to-Left based languages. We have custom CSS to handle if the documentation language is specified as RTL or not to handle this. In the future, I'd like to consider moving toward furo, however I'd rather not recreate the complex CSS required for RTL support.

I'd like to request RTL CSS be added to furo.

[pradyunsg]

I'd be very happy to accept a PR for this. If someone could provide a demo documentation, with instructions on how to perform the build, that'd be great too! :)

[pradyunsg]

@Daltz333 Could you provide me with an RTL documentation set for me to test with?

[Daltz333]

This is our current RTL documentation set. If you'd like, I can open a branch with it currently in furo.

https://docs.wpilib.org/he/stable/

[pradyunsg]

Ah thanks!

For future self-reference, the steps to build those docs with a specific language are at https://github.com/wpilibsuite/frc-docs-translations/#building-locally.