Add info about underlying libappindicator version

Author: purejava

README.md

@@ -6,11 +6,13 @@
 
 Java bindings for libappindicator-gtk3 in 100% pure Java
 
+Based on libappindicator3-1 (12.10.1+20.10.20200706.1-0ubuntu1)
+
 # Requires
 Java 19 (preview)
 - due to the use of the new Foreign Function & Memory API
 
 # Copyright
 Copyright (C) 2023 Ralph Plawetzki
 
-The libappindicator-gtk3-java logo is made from [Icon Fonts](http://www.onlinewebfonts.com/icon) and is licensed by CC BY 3.0
+The libappindicator-gtk3-java logo is made from [Icon Fonts](http://www.onlinewebfonts.com/icon) and is licensed by CC BY 3.0