Add comment as response to common mistake

Overv · Overv · commit 839fb327de0d · 2019-03-14T21:08:56.000+01:00
diff --git a/03_Drawing_a_triangle/01_Presentation/01_Swap_chain.md b/03_Drawing_a_triangle/01_Presentation/01_Swap_chain.md
@@ -91,6 +91,8 @@ createInfo.enabledExtensionCount = static_cast<uint32_t>(deviceExtensions.size()
 createInfo.ppEnabledExtensionNames = deviceExtensions.data();
 ```
 
+Make sure to replace the existing line `createInfo.enabledExtensionCount = 0;` when you do so.
+
 ## Querying details of swap chain support
 
 Just checking if a swap chain is available is not sufficient, because it may not
