added xUnit Tests

MyHelloWorld.Tests/UnitTest1.cs

@@ -0,0 +1,21 @@
+using Xunit;
+using MyHelloWorld; // Dein Namespace der Haupt-App
+
+namespace MyHelloWorld.Tests
+{
+    public class HelloTests
+    {
+        [Fact]
+        public void GetGreeting_ShouldReturnCorrectText()
+        {
+            // Arrange
+            var generator = new HelloGenerator();
+
+            // Act
+            var result = generator.GetGreeting();
+
+            // Assert
+            Assert.Equal("Hello World", result);
+        }
+    }
+}