Adjust image width in README.md

Updated the image width in README.md for better display.

Author: vim-zz

README.md

@@ -6,7 +6,7 @@ A lightweight native macOS utility for running scripts and commands in the backg
 
 If you’ve ever left a Terminal window open _“just to keep a command running”_, this app is for you.
 
-<img src="something_bg_menu.png" alt="Menu Bar Screenshot" width="400">
+<img src="something_bg_menu.png" alt="Menu Bar Screenshot" width="600">
 
 ## Repository layout