✨ Add sitemap and stress test index files

- Introduced a new sitemap.xml for better SEO management.
- Added Index.razor for performance testing with k6.

Author: ajaysskumar

TestArena/Blog/Common/NavigationUtils/SiteMap.cs

@@ -128,6 +128,12 @@ public static class SiteMap
             new DateTime(2025, 8, 09),
             "images/blog/performance-testing/basic-setup/banner.png",
             ["Performance Testing", "K6", "API", ".NET"]),
+            
+        new("Performance Testing for APIs: Stress testing with K6",
+            "/blog/performance-testing/stress-test-with-k6",
+            new DateTime(2025, 8, 16),
+            "images/blog/performance-testing/stress-test/banner.png",
+            ["Performance Testing", "K6", "API", ".NET", "Stress Test"]),
         ];
 
         public static IEnumerable<PageInfo> PublishedArticles => Pages.Where(p => p.IsPublished && p.PublishedOn <= DateTime.UtcNow);