Provide a good example for using 'setState' in NotebookRendererApi

[miguelsolorio]

Testing #99001

Maybe this is just my lack of understand with the notebook API, but all of the other methods in INotebookRendererApi seem to have clear instructions on what they're used for (onWillDestroyCell and onDidCreateCell are good examples). But for setState and getState I'm a bit unsure of how i'm suppose to use this. It seems as if once I set this in the entry point for the renderer the state is persisted, so this makes it a bit ambiguous on its use. Maybe if there was a good example for this.

[connor4312]

Thanks, merging into #99320. I want to move those types from a copypasta'd .d.ts into its own package with appropriate documentation 🙂