Add Aspire upgrade code samples

AspireVersionUpgrade/Aspire8App/AspireApp.AppHost/Program.cs

@@ -0,0 +1,16 @@
+var builder = DistributedApplication.CreateBuilder(args);
+
+var password = builder.AddParameter("password", secret: true);
+var sql = builder.AddSqlServer("sql", password);
+var sqldb = sql.AddDatabase("sqldb");
+
+var apiService = builder
+    .AddProject<Projects.AspireApp_ApiService>("apiservice")
+    .WithReference(sqldb);
+
+
+builder.AddProject<Projects.AspireApp_Web>("webfrontend")
+    .WithExternalHttpEndpoints()
+    .WithReference(apiService);
+
+builder.Build().Run();