Update README.md

DemoUnity/README.md

@@ -11,13 +11,19 @@ In default, the link length is set 2, but it can be changed before startup by us
 
 ### Example for startup configuration
 
-Assume the execution file name is robotdemo.exe  
+*Assume the execution file name is robotdemo.exe*  
 startup with link length setting  
-    robotdemo.exe -link1 1.8 -link2 2.1 -link3 1.9  
-startup with endpoint movement speed setting  
-    robotdemo.exe -speed 0.2  
-startup with both link length and movement speed  
-    robotdemo.exe -link1 1.8 -link2 2.1 -speed 0.02  
+``` Shell
+    robotdemo.exe -link1 1.8 -link2 2.1 -link3 1.9
+```    
+Startup with endpoint movement speed setting  
+``` Shell
+    robotdemo.exe -speed 0.2
+```
+Startup with both link length and movement speed  
+``` Shell
+    robotdemo.exe -link1 1.8 -link2 2.1 -speed 0.02
+```
 
 [**Release output is upload to the github**](https://github.com/zhuchen115/Kinematics/releases)