added firebase and rudimentary leaderboard support

addons/godot-firebase/remote_config/remote_config.gd

@@ -0,0 +1,14 @@
+class_name RemoteConfig
+extends RefCounted
+
+var default_config = {}
+
+func _init(values : Dictionary) -> void:
+	default_config = values
+	
+func get_value(key : String) -> Variant:
+	if default_config.has(key):
+		return default_config[key]
+	
+	Firebase._printerr("Remote config does not contain key: " + key)
+	return null