add resize doc

[trebor]

adding doc for resize. @mbostock i'm adding you for review here as i wanted to be sure i wasn't missing nuance on resize()

[mbostock]

Can we just say

`resize`

instead of

**`resize()`**

when referencing the resize function? I don’t think we need so many different special typographic treatments.

[mbostock]

Also, and apologies for the duplicate effort, but I just added documentation for resize as part of #555 by way of moving it from the Dash library to the standard library.

I do think it would be nice to document the special behavior with one argument (width), the use of position: absolute to prevent a feedback loop, the support for the invalidation promise as an optional argument after the render function, the fact that it uses ResizeObserver under the hood, the fact that it requires a wrapper element, etc. But also not a high priority.

[trebor]

no worries. how about i wait for #555 to land then i can reconcile what's in there and the suggestions above.

[trebor]

@mbostock i've added the width only case and restyled it to match the other component docs. it looks like this now:

i'm merging this up into components so we can move that all along. we change/remove this section if winds up redundant.