add comments

main.go

@@ -503,6 +503,8 @@ func main() {
 		} else if key.KeyVal() == gdk.KEY_Return {
 			s, _ := searchEntry.GetText()
 			if s != "" {
+				// Check if the search box content is an arithmetic expression. If so, display the result
+				// and copy to the clipboard with wl-copy.
 				result, err := expr.Eval(s, nil)
 				if err == nil {
 					log.Debugf("Setting up mathemathical operation result window. Operation: %s, result: %v", s, result)

uicomponents.go

@@ -599,6 +599,7 @@ func setUpOperationResultWindow(operation string, result string) {
 		layershell.SetKeyboardMode(win, layershell.LAYER_SHELL_KEYBOARD_MODE_EXCLUSIVE)
 	}
 
+	// any key to close the window
 	win.Connect("key-release-event", func(_ *gtk.Window, event *gdk.Event) bool {
 		win.Destroy()
 		return true