Add C# example to challenge in order-limit.mdx

Author: LuceCarter

docs/40-CRUD/3-ORDER-LIMIT.mdx

@@ -86,5 +86,18 @@ This returns the **top 10 available books** in the "Science Fiction" genre.
         ```
       </div>
     </TabItem>
+    <TabItem value="csharp" label="C#">
+      <div>
+        ```csharp
+        var projection = Builders<Book>.Projection.Include(b => b.Title).Include(b => b.Pages);
+        var descendingPagesSort = Builders<Book>.Sort.Ascending("title");
+
+        List<Book> sortedBooksLimitedToTen = booksCollection.Find(b => true) // Empty filter to find all books
+        .Project<Book>(projection)
+        .Sort(descendingPagesSort)
+        .Limit(10).ToList();
+        ```
+      </div>
+    </TabItem>
   </Tabs>
 </details>