schema is not an html attribute

[graingert]

Reasons for making this change

schema is not an html attribute

Checklist

• I'm updating documentation
  • I've checked the rendering of the Markdown text I've added
  • If I'm adding a new section, I've updated the Table of Content
• I'm adding or updating code
  • I've added and/or updated tests
  • I've updated docs if needed
  • I've run npm run cs-format on my branch to conform my code to prettier coding style
• I'm adding a new feature
  • I've updated the playground with an example use of the feature

[epicfaace]

Thanks for the catch @graingert ! Can you make your change in the new docs folder, https://github.com/mozilla-services/react-jsonschema-form/blob/master/docs/form-customization.md, instead of README.md?

[epicfaace]

@graingert just bumping this!

[graingert]

@epicfaace can you take over this?