Support for observable notebooks about typescript-notebook

[GordonSmith]

@DonJayamanne I recently went through this exercise for the ECL language / notebook (not quite released) and am looking at doing an observable JS notebook in its own right as well.

Some comments:
To add viz to a language I treat each observable cell as a complete "observable notebook", which may be counter intuitive for experienced observable folks - but makes a lot more sense from an ECL (or TypeScript) developers point of view...

[DonJayamanne]

Not gong to do this, this extension focuses on node.js as the runtime and observable notebooks doesn't use pure JS (see here https://observablehq.com/@observablehq/observables-not-javascript).
Hence not going ahead trying to squeeze a round peg into a square hole.

Also there are challenges in exposing data from node.js kernel into the observable (browser) environment. This can be done, but the challenge is making this user friendly & intuitive (right now I don't see much of a use case for this, no user requests, haven't seen requests on various channels, hence not doing this)

However supporting that as a renderer I something I'm open to, but not in this issue.

[RandomFractals]

That would be awesome. @GordonSmith built this great OJS extension that handles those notebook code cells and previews in JS and md formats: https://github.com/GordonSmith/vscode-ojs

I think we only need Observable kernel that takes into account OJS notebooks cell reactivity to close that loop.

[RandomFractals]

yeah, OJS is not very standard and would require a completely new custom kernel to make those notebooks load and work. Probably best to do that in a separate OJS notebooks extension.

[GordonSmith]

"However supporting that as a renderer I something I'm open to" - this is what I am doing in my ECL plugin, pass the source straight through to the renderer and use @hpcc-js/observable-md to render it...