Update README.md

Author: makerbase-mks

README.md

@@ -3,10 +3,10 @@
 USE IAR IDE tool build it
 - Download this firmware
 - Open workspace. "File -> Open -> Workspace"
-![1-Open-Workspace](https://github.com/makerbase-mks/MKS-Robin-Nano-Firmware/blob/master/Picture/1-Open-Workspace.png "1-Open-Workspace")
+![1-Open-Workspace](https://github.com/makerbase-mks/MKS-Robin-Nano-Firmware/blob/Nano-firmware-v2.x.x/Picture/1-Open-Workspace.png "1-Open-Workspace")
 - Build firmware. "Project -> Build All",Build done, MKS-Robin-Nano-Firmware\EWARM\mksRobinNano\Exe the path will generate a ***.bin file
-![2-Build](https://github.com/makerbase-mks/MKS-Robin-Nano-Firmware/blob/master/Picture/2-Build.png "2-Build")
-![3-bin](https://github.com/makerbase-mks/MKS-Robin-Nano-Firmware/blob/master/Picture/3-bin.png "3-bin")
+![2-Build](https://github.com/makerbase-mks/MKS-Robin-Nano-Firmware/blob/Nano-firmware-v2.x.x/Picture/2-Build.png "2-Build")
+![3-bin](https://github.com/makerbase-mks/MKS-Robin-Nano-Firmware/blob/Nano-firmware-v2.x.x/Picture/3-bin.png "3-bin")
 # How update firmware 
 - Encrypted firmware. 
 - Copy ***.bin file to TF card, inste board, Power on to update firmware