Merge pull request #211 from vala-lang/simplify-sample-code

Remove redundant `target-glib` flag from code sample compile command

assets/code-sample.md

@@ -23,5 +23,5 @@ public class ExampleApp : Gtk.Application {
 }
 
 // Compile command (requires gtk4 package to be installed):
-// valac --target-glib=auto --pkg gtk4 ExampleApp.vala
+// valac --pkg gtk4 ExampleApp.vala
 ```