fix: update ts and fix typing issues

[domoritz]

@arvind it looks like fields wasn't in interval selection configs but the docs and tests say it's a shared config option. Does this look right to you that I moved filelds?

[lsh]

Looks good, thanks!

[joelostblom]

This PR added the fields param to the interval selection config, but the docs say that interval selections only work with encodings and not fields. After this PR, fields now show up as an accepted parameter in interval selections, but setting it does not seem to have an effect Open the Chart in the Vega Editor. Should we remove fields from the interval config until it works to create a spec such as in the linked chart?

[arvind]

Sorry that this slipped off my radar (I was on vacation the week the PR was issued and then subsequently merged). fields is not a valid property of interval selections—they only take encodings as @joelostblom mentioned.

[domoritz]

I see. We should undo the specific change then. https://vega.github.io/vega-lite/docs/selection.html#selection-props is incorrect then, right?