added a figure for directories tree
added a figure for directories tree

attatrol/Orekit,Yakushima/Orekit,wardev/orekit,Yakushima/Orekit,ProjectPersephone/Orekit,CS-SI/Orekit,liscju/Orekit,petrushy/Orekit,ProjectPersephone/Orekit,attatrol/Orekit,treeform/orekit,CS-SI/Orekit,petrushy/Orekit,liscju/Orekit