why the code has container

[curran]

As a user editing a V3 viz, I want to be informed as to what is going on, so that I can understand how to move forward using the V3 runtime.

Original question by @nitanagdeote :

I started writing code but did not understand why there was a container. I tried to look for video, can't find it. Why don't we have a resources page and one section for documentation?

[curran]

This pattern is explained in the first video of the new series

https://www.youtube.com/watch?v=bZhWCO-bDek&list=PL9yYRbwpkykthTFJl9vYr_C0FCjRIn_7G

Maybe the viz page should flag to the user something like "Hey this is a V3 viz and supports hot reloading! To learn about the main function and its arguments (container, {state, setState}), see this reference example".