fix: added command line argument to successfully run multiwindow example (#3717)

Co-authored-by: Lucas Fernandes Nogueira <lucas@tauri.studio>

examples/multiwindow/README.md

@@ -2,4 +2,4 @@
 
 An example Tauri Multi-Window Application.
 
-To execute run the following on the root directory of the repository: `cargo run --example multiwindow`.
+To execute run the following on the root directory of the repository: `cargo run --example multiwindow --features window-create`.