Update SETUP.md

.github/SETUP.md

@@ -1,15 +1,3 @@
-# Poop Journal
-
-![coverage][coverage_badge]
-[![style: very good analysis][very_good_analysis_badge]][very_good_analysis_link]
-[![License: MIT][license_badge]][license_link]
-
-Generated by the [Very Good CLI][very_good_cli_link] 🤖
-
-Poop Journal
-
----
-
 ## Getting Started 🚀
 
 This project contains 3 flavors:
@@ -31,7 +19,13 @@ $ flutter run --flavor staging --target lib/main_staging.dart
 $ flutter run --flavor production --target lib/main_production.dart
 ```
 
-_\*Poop Journal works on iOS, Android, Web, and Windows._
+
+
+---
+
+## Setting up Firebase 🔥
+
+The placeholder files `firebase.json` and `android/app/google-services.json` need to be replaced with valid ones.
 
 ---