add script to restore manual-edited files after cubeMX code generating (#82)

target_f1/cubemx_restore.sh

@@ -0,0 +1,5 @@
+git checkout -- target_f1/Middlewares/Third_Party/FreeRTOS/Source/CMSIS_RTOS/cmsis_os.h
+git checkout -- target_f1/Makefile
+git checkout -- target_f1/Src/stm32l4xx_it.c
+git checkout -- target_f1/Src/usbd_conf.c
+git checkout -- target_f1/Src/usbd_desc.c