📝 Add changelog entry

Author: Schneegans

docs/changelog.md

@@ -30,6 +30,7 @@ This changelog follows the rules of [Keep a Changelog](http://keepachangelog.com
 - A button in the icon-picker popover to **reload all icon themes** without restarting Kando.
 - The command line flag `--reload-icon-themes` which can be used to tell a running Kando instance to reload all icon themes.
 - A setting to **enable or disable the drawing of selection wedges** in supported menu themes. This can be found in the theme-settings dialog. It is disabled by default as the selection wedges are quite resource-intensive to draw currently.
+- A new `--close-menu` command line flag which closes the currently opened menu. Thanks to [@yar2000T](https://github.com/yar2000T) for this contribution!
 - Many translation updates: **Thanks to all the contributors!**
 - Add support for GNOME's classic mode.
 - The possibility to change the label color of the "Rainbow Labels" theme.