Update project.godot files to latest format

2d/navigation/project.godot

@@ -1,3 +1,11 @@
+; Engine configuration file.
+; It's best edited using the editor UI and not directly,
+; since the parameters that go here are not all obvious.
+; 
+; Format: 
+;   [section] ; section goes between []
+;   param=value ; assign values to parameters
+
 config_version=3
 
 [application]
@@ -8,7 +16,10 @@ config/icon="res://icon.png"
 
 [display]
 
+window/size/width=800
 stretch/aspect="keep"
 stretch/mode="2d"
-window/size/height=600
-window/size/width=800
+
+[gdnative]
+
+singletons=[  ]