improve live code chapter

[rlanzafame]

propose to take current live code page and replace it with:

• overview page explaining the tools we use and how to choose one for your application
• subpages describing specific tools, at minimum one page for sphinx-thebe and jupyterlite

do this once teachbooks-sphinx-thebe is ready so that a high level description can be added. can also use documentation that is being prepared by Diana.

[Tom-van-Woudenberg]

Sure! Although before we deliberately removed the jupyterlite pages, but we can add them back in

[rlanzafame]

oh good point, i'll take a look at those when we revise the chapter. part of the reason we removed them was that we gave up trying to embed the jupyterlite feature into the built book during the build process. we can try again (i'm curious), but at the moment i was only thinking of the "use it as a separate website/repo" situation (like the Learn Python calculator).

[rlanzafame]

if we use it in the book, add back jupyterlite-sphinx to requirements.txt