Make SharpIDE.Photino project deprecation clearer

src/SharpIDE.Photino/Program.cs

@@ -9,11 +9,13 @@ using SharpIDE.Photino.Services;
 
 namespace SharpIDE.Photino;
 
+// This C# project is deprecated and serves as a reference only - see the SharpIDE.Godot project
 public class Program
 {
 	[STAThread]
 	public static void Main(string[] args)
 	{
+		throw new NotSupportedException("This project is deprecated and serves as a reference only - see the SharpIDE.Godot project");
 		var appBuilder = PhotinoBlazorAppBuilder.CreateDefault(args);
 
 		appBuilder.Services.AddLogging();//

src/SharpIDE.Photino/README.md

@@ -1,4 +1,4 @@
-## SharpIDE.Photino
+## [DEPRECATED] SharpIDE.Photino
 
 This was my first attempt with Blazor and Photino, before reaching the point
 of needing to work with the monaco editor and javascript, and deciding to reimplement the UI in Godot.