Since it's more reliable (and strict) at code formatting than ESLint.
We use it via an ESLint plugin, and so disable the style-related AirBnB
preset rules, leaving the AirBnB guide to handle only correctness and
best practices rules.
It's highly encouraged to use an IDE integration or Git commit hook
to run Prettier (or `yarn lint --fix`) automatically. See:
* https://prettier.io/docs/en/editors.html
* https://prettier.io/docs/en/precommit.html
We may consider enabling a git commit hook out of the box (using eg
Husky) in the future, however they have previously been known to
interfere with partial-staging workflows, so would need to test the
fixes they have made for them thoroughly first.
In future PRs we may also want to start formatting JSON/CSS/Markdown
using Prettier too.