Added a dynamic layout system where UI elements can be moved about on a tiled grid.

components/layout_library.tscn

@@ -0,0 +1,66 @@
+[gd_scene format=3]
+
+[ext_resource type="Script" path="res://scripts/layout_library.gd" id="1"]
+
+[node name="LayoutLibrary" type="PanelContainer"]
+visible = false
+z_index = 300
+layout_mode = 1
+anchor_left = 1.0
+anchor_right = 1.0
+offset_left = -424.0
+offset_top = 80.0
+offset_right = -24.0
+offset_bottom = 720.0
+theme_type_variation = &"VehicleBackground"
+script = ExtResource("1")
+
+[node name="Margin" type="MarginContainer" parent="."]
+layout_mode = 2
+theme_override_constants/margin_left = 16
+theme_override_constants/margin_right = 16
+theme_override_constants/margin_top = 12
+theme_override_constants/margin_bottom = 12
+
+[node name="Body" type="VBoxContainer" parent="Margin"]
+layout_mode = 2
+theme_override_constants/separation = 12
+
+[node name="Header" type="HBoxContainer" parent="Margin/Body"]
+layout_mode = 2
+
+[node name="Title" type="Label" parent="Margin/Body/Header"]
+layout_mode = 2
+size_flags_horizontal = 3
+text = "ELEMENT LIBRARY"
+theme_override_font_sizes/font_size = 20
+
+[node name="Close" type="Button" parent="Margin/Body/Header"]
+layout_mode = 2
+text = "×"
+tooltip_text = "Close library"
+
+[node name="List" type="ItemList" parent="Margin/Body"]
+custom_minimum_size = Vector2(0, 180)
+layout_mode = 2
+size_flags_vertical = 3
+theme_type_variation = &"LayoutLibraryList"
+same_column_width = true
+fixed_icon_size = Vector2i(24, 24)
+
+[node name="Description" type="Label" parent="Margin/Body"]
+custom_minimum_size = Vector2(0, 78)
+layout_mode = 2
+autowrap_mode = 3
+
+[node name="Size" type="Label" parent="Margin/Body"]
+layout_mode = 2
+
+[node name="Status" type="Label" parent="Margin/Body"]
+layout_mode = 2
+autowrap_mode = 3
+
+[node name="Add" type="Button" parent="Margin/Body"]
+layout_mode = 2
+text = "Add element"
+tooltip_text = "Place in the first available space, using the minimum size if needed"