Allow live editing of the code in examples\demos

[TonyIvanova]

It would much more convenient to use docs if they would allow live code browsing and editing (at least for demos).
For example like in antvg6 library documentation:

There is this play button in some of the code blocks, but it doesn't always work and I bet no one is noticing it

Also it would be very helpful to add to each category of styles an interactive example.

[TonyIvanova]

@maxkfranz what do you think about this change in documentation? Is it something worth doing? If yes - I can open an issue and try to do that for demos.