Add .NET docs to Postrgres connection examples

postgres/connecting/app-connection-examples.html.markerb

@@ -371,3 +371,50 @@ if (config.use_env_variable) {
   }
 ```
 </details>
+
+## Connecting with .NET - EF Core & Npgsql
+[docs](https://www.npgsql.org/efcore/index.html?tabs=onconfiguring#configuring-the-project-file)
+
+Minimal parsing setup using the `DATABASE_URL` environment variable provisioned automatically with attaching a pg app. In ```Program.cs```:
+
+```csharp
+builder.Services.AddDbContext<ApplicationDbContext>(options =>
+{
+    var databaseUrl = Environment.GetEnvironmentVariable("DATABASE_URL");
+    if (!string.IsNullOrEmpty(databaseUrl))
+    {
+            Uri uri;
+
+            try
+            {
+                uri = new Uri(databaseUrl);
+            }
+            catch (UriFormatException ex)
+            {
+                throw new InvalidOperationException(
+                    "The DATABASE_URL environment variable is not a valid URI.",
+                    ex
+                );
+            }
+
+            var userInfo = uri.UserInfo.Split(':');
+            var dbUserFromUrl = userInfo[0];
+            var dbPwFromUrl = userInfo.Length > 1 ? userInfo[1] : "";
+            var dbHostFromUrl = uri.Host;
+            var dbPortFromUrl = uri.Port > 0 ? uri.Port.ToString() : "5432";
+            var dbNameFromUrl = uri.AbsolutePath.TrimStart('/');
+
+            // Extract sslmode if present
+            var sslMode = "Require";
+            var query = HttpUtility.ParseQueryString(uri.Query);
+            if (!string.IsNullOrEmpty(query["sslmode"]))
+            {
+                sslMode = query["sslmode"];
+            }
+
+            var npgsqlConn =
+                $"Host={dbHostFromUrl};Port={dbPortFromUrl};Database={dbNameFromUrl};Username={dbUserFromUrl};Password={dbPwFromUrl};SSL Mode={sslMode};Trust Server Certificate=true";
+            options.UseNpgsql(npgsqlConn);
+    }
+});
+```