DOCS: readme diagram update, HW installation guide (#2427)

* DOCS: readme diagram update, HW installation guide

* DOCS: image update to HW installation guide

README.md

@@ -215,7 +215,7 @@ Apollo 3.5 is capable of navigating through complex driving scenarios such as re
 
 * **Hardware/ Vehicle Overview**
 
-![image alt text](docs/demo_guide/images/Hardware_overview.png)
+![image alt text](docs/demo_guide/images/Hardware_overview_3_5.png)
 
 * **Hardware Connection Overview**
 

docs/quickstart/apollo_3_5_hardware_system_installation_guide.md

@@ -158,9 +158,9 @@ The list of prerequisites are as follows:
 
 The following two diagrams indicate the locations of where the three major components (GPS Antenna, IPC, GPS Receiver and LiDAR) should be installed on the vehicle:
 
-![major_component_side_view](https://github.com/ApolloAuto/apollo/blob/master/docs/demo_guide/images/Hardware_overview.png)
+![major_component_side_view](images/Hardware_overview_3_5.png)
 
-![major_component_rear_view](images/Car_Rearview.png)
+![major_component_rear_view](images/car_rearview_3_5.png)
 
 ## Additional Tasks Required