message: add installation requirements
diff: @@ -19,6 +19,14 @@ supported. More coming soon, for comprehensive list see ROADMAP.md.
  ## Setup instructions
  +### Installation requirements
  +
  +Make sure you have the following installed:
  +
  +- [Git](https://git-scm.com/downloads)
  +- [Node](https://nodejs.org/en/download/) 10, 11, or 12
  +- [Yarn](https://classic.yarnpkg.com/en/docs/install/)
  +
  ### 1. Create and set up a Firebase project
  - Create a new project using the
  