React: Better docs for `<select multiple/>`

[zpao]

From #671:

@zpao The docs on forms could be clearer by mentioning that you can put an array into the value attribute (the usage example is likely to be <select multiple>).

cc @sompylasar

[chenglou]

Fixed.

[gaearon]

Reopening because new docs don't have that info, and it is confusing.
We should re-add it.

[ghost]

I am looking to make my first contribution and would like to fix this issue.

[hawkins]

I also opened a PR for this on #9539 last week, restoring the original note.

I added notes for discussion on a more thorough example on the PR, like the current <select> example has, but have not done much beyond that. Do we think that such an example would be beneficial? I almost think not, since the difference is just treating value as an array with multiple, but I'm curious to hear everyone else's thoughts on that.

[hawkins]

There hasn't been any further discussion in PR #9539 or on this issue in the last two months, so is that PR all we need to do for this?

cc @gaearon

[gaearon]

Sorry. We’ve been busy with a rewrite for React 16, and haven’t been actively reviewing the PRs.

[gaearon]

Fixed in https://github.com/facebook/react/pull/9539.

[hawkins]

No sweat, I figured as much. React 16 was absolutely worth it, great work! 🎉