🐛 Fix missing firebase.config.js in build process

Author: leolabs

netlify.toml

@@ -1,3 +1,3 @@
 [build]
-  command = "echo $SPOTIFY_CONFIG > spotify.config.js && yarn build"
-  publish = "build"
+  command = "echo $SPOTIFY_CONFIG > spotify.config.js && echo $FIREBASE_CONFIG > firebase.config.js && yarn build"
+  publish = "build"