fix image segmentation read me

official/lite/image_segmentation/README.md

...lite/image_segmentation/app/libs/mindspore-lite-1.6.0.aar

...e/image_segmentation/app/src/main/assets/segment_model.ms

.../lite/image_segmentation/images/lite_quick_start_home.png

...egmentation/images/lite_quick_start_project_structure.png

...te/image_segmentation/images/lite_quick_start_run_app.PNG

...entation/images/lite_segmentation_quick_start_install.png

official/lite/image_segmentation/images/segmentation1.png

official/lite/image_segmentation/images/segmentation2.png

official/lite/image_segmentation/images/segmentation3.png

official/lite/image_segmentation/images/segmentation4.png

official/lite/image_segmentation/images/segmentation5.png

official/lite/image_segmentation/images/segmentation6.png

official/lite/image_segmentation/images/segmentation7.png