message: Add coding guidelines to CONTRIBUTING
diff: @@ -64,6 +64,14 @@ So...feel ready to jump in? Let's do this. Head over to the [Getting Started gui
  If you need help, just jump into our [Discord chatroom](https://discord.gg/MUpMjP2).
  +# Coding Guidelines
  +
  +All code is formatted with `prettier` using the configuration in the repo. If possible we recommend configuring your editor to format automatically, but you can also use the `yarn prettier --write <file>` command to format files.
  +
  +If you're contributing to the backend or CLI tooling, be mindful of cross-platform support. [This](https://shapeshed.com/writing-cross-platform-node/) blog post is a good guide of what to keep in mind when writing cross-platform NodeJS.
  +
  +Also be sure to skim through our [ADRs](https://github.com/spotify/backstage/tree/master/docs/architecture-decisions) to see if they cover what you're working on. In particular [ADR006: Avoid React.FC and React.SFC](https://github.com/spotify/backstage/blob/master/docs/architecture-decisions/adr006-avoid-react-fc.md) is one to look out for.
  +
  # Code of Conduct
  This project adheres to the [Spotify FOSS Code of Conduct][code-of-conduct]. By participating, you are expected to honor this code.
  