Add CLI runtime on docs

[mtuchi]

Description

For CLI work through it will be nice to have playground sections that are either embed or linked to a playground environment,

Resources to explore

• https://runkit.com/home
• https://replit.com/pricing
• https://stackblitz.com/
• https://codesandbox.io/
• Interesting blog

[josephjclark]

What about linking straight into the demo build of Lightning?

[mtuchi]

What about linking straight into the demo build of Lightning?

I second this 👍🏽 , My wish is having a fully interactive experience on docs page, Similar to https://livebook.dev/ or resources listed above. But that requires a lot design thinking