Add description to plugin

Author: gilzoide

addons/csharp_gdextension_bindgen/plugin.cfg

@@ -1,7 +1,7 @@
 [plugin]
 
 name="C# GDExtension Bindgen"
-description=""
+description="Automatic C# bindings generator for GDExtension classes (Godot 4.4+)"
 author="gilzoide"
 version="0.1.0"
 script="csharp_gdextension_bindgen.gd"