* Minor: context/theme-detailed-app.js broken
Today I tested out the new Context API using using [CRA](https://github.com/facebook/create-react-app).
I encountered a runtime exception, so this tiny PR is intended to make it easier for future Context API learners.
`ReferenceError: Must call super constructor in derived class before accessing 'this' or returning from derived constructor`
create-react-app@next commit da518d2238298dd5db74e9c63c12251099f87bb0
* Update theme-detailed-app.js
When a new `id` prop is passed in, `getDerivedStateFromProps` sets `this.state.externalData` to `null`. If I understand the new API correctly the return value of gDSFP() either becomes the new state or is merged into the new state? If so, then `componentDidUpdate` should examine the new state (`this.state.externalData`), not `prevState.externalData`.
* Use correct component name in context doc example
I'm assuming the intention was to reference the `FancyButton` component defined directly above, unless I'm misunderstanding how to read this example.
* Prettier
- Move Motivation to top @bvaughn
- Copy in some Motivation text from the RFC for the intro para
- Update examples
- Remove state from simple example
- Remove "random color" example;
just toggle a theme variable instead
- Update highlights
Toru Kobayashi
Chanyeon Kim
Pat
Nathan Quarles
Christian Maughan Tegnér
Brian Vaughn
Dan Abramov
Alex Krolick