[docs] Fix spelling mistake in PropTypeDescription.js

[Jbarget]

Fixes #5882

• PR has tests / docs demo, and is linted.
• Commit and PR titles begin with [ComponentName], and are in imperative form: "[Component] Fix leaky abstraction".
• Description explains the issue / use-case resolved, and auto-closes the related issue(s) (http://tr.im/vFqem).

[mbrookes]

Thanks for the PR. I've made some changes to the title and description so that the ticked-boxes are actually valid (just ticking them doesn't make it so 😄 )

Not sure what's going on with the tests though.

[Jbarget]

haha @mbrookes, apologies!
failing CI seems to be because of Cannot find module 'react/lib/EventPluginHub' when it tries to run npm test

[Jbarget]

@oliviertassinari any idea why it might be having issues with running npm test?

[mbrookes]

@Jbarget We don't need tests for a typo anyway, so merging as is.

[mbrookes]

Actually @oliviertassinari, even with the typo corrected the wording is a bit ambiguous. Would something like:

"Any other properties supplied will be spread to the root element."

be better?

[oliviertassinari]

@mbrookes That sounds good. We could change that on the next branch 👍 .