Document memoization as alternative to componentWillReceiveProps

[gaearon]

We get a lot of feedback that getDerivedStateFromProps is used for memoization which is not very ergonomic.

Let’s add a recipe about memoizing directly to the docs.

https://twitter.com/brian_d_vaughn/status/987443099537309696?s=20

We should probably use this package:

https://www.npmjs.com/package/memoize-one

It’s important to highlight that we usually recommend memoizing just the last value.

[KenFoss]

@gaearon Can I take this?