added firebase and rudimentary leaderboard support

UI/authentication.tscn

@@ -0,0 +1,66 @@
+[gd_scene load_steps=3 format=3 uid="uid://b6nt3p1kntjod"]
+
+[ext_resource type="Script" uid="uid://cbmnj1dfgfwp5" path="res://scripts/authentication.gd" id="1_bgnbp"]
+[ext_resource type="Theme" uid="uid://clek42ofxr45f" path="res://DefaultTheme.tres" id="2_hbvo2"]
+
+[node name="Authentication" type="Control"]
+layout_mode = 3
+anchors_preset = 15
+anchor_right = 1.0
+anchor_bottom = 1.0
+grow_horizontal = 2
+grow_vertical = 2
+script = ExtResource("1_bgnbp")
+
+[node name="ColorRect" type="ColorRect" parent="."]
+layout_mode = 1
+anchors_preset = 15
+anchor_right = 1.0
+anchor_bottom = 1.0
+grow_horizontal = 2
+grow_vertical = 2
+color = Color(0, 0, 0, 1)
+
+[node name="VBoxContainer" type="VBoxContainer" parent="."]
+layout_mode = 1
+anchors_preset = 8
+anchor_left = 0.5
+anchor_top = 0.5
+anchor_right = 0.5
+anchor_bottom = 0.5
+offset_left = -441.0
+offset_top = -351.5
+offset_right = 441.0
+offset_bottom = 351.5
+grow_horizontal = 2
+grow_vertical = 2
+theme = ExtResource("2_hbvo2")
+theme_override_constants/separation = 34
+alignment = 1
+
+[node name="StateLabel" type="Label" parent="VBoxContainer"]
+unique_name_in_owner = true
+layout_mode = 2
+text = "Not Logged In"
+
+[node name="email_edit" type="LineEdit" parent="VBoxContainer"]
+unique_name_in_owner = true
+layout_mode = 2
+placeholder_text = "Email"
+
+[node name="password_edit" type="LineEdit" parent="VBoxContainer"]
+unique_name_in_owner = true
+layout_mode = 2
+placeholder_text = "Password"
+secret = true
+
+[node name="log_in" type="Button" parent="VBoxContainer"]
+layout_mode = 2
+text = "Log In"
+
+[node name="sign_up" type="Button" parent="VBoxContainer"]
+layout_mode = 2
+text = "Sign Up"
+
+[connection signal="pressed" from="VBoxContainer/log_in" to="." method="_on_log_in_pressed"]
+[connection signal="pressed" from="VBoxContainer/sign_up" to="." method="_on_sign_up_pressed"]