Shared prettier configuration

$ yarn add --dev @shopify/prettier-config

Shopify’s shared prettier config comes bundled in @shopify/prettier-config. To enable these rules, add a prettier property in your package.json and reference this shared config as follows:

"prettier": "@shopify/prettier-config"

Previously, rules had been defined directly in a .prettierrc or package.json

Any previous .prettierrc should be removed in favour of the shared config.