Editor/MyEditorMenu.cs

An editor-only static class that adds a menu item under Editor -> Performant Terrain Scatterer/My Menu Option. When selected it shows an editor dialog saying "It worked!" and a message that the call came from the library's editor code.

File Access
using Editor;

public static class MyEditorMenu
{
	[Menu( "Editor", "Performant Terrain Scatterer/My Menu Option" )]
	public static void OpenMyMenu()
	{
		EditorUtility.DisplayDialog( "It worked!", "This is being called from your library's editor code!" );
	}
}