Long scripts == Slow Interface

[asteroidb612]

We can stress-test the app with a long script, like this one:
https://www.blumenthalarts.org/assets/doc/Hamilton-Lyrics-ACT-I1-e82b4f261a.pdf

It's not unrealistic - there are versions of Hamlet with 4000 lines! We render one DOM node per line, and 3000 nodes get slow quickly. Not even Html.Lazy can save us ;)

One fix may be to only render the nodes that would be on the screen at a given moment. This is tricky to get right! We'll figure it out if people find a good use case for big scripts.

[asteroidb612]

Another source for some directions https://discourse.elm-lang.org/t/performance-optimization/5105