Update README.md

README.md

@@ -25,10 +25,13 @@ docker compose down
 # the Ubuntu 20.04 desktop running inside the Docker container.
 cd ~/workspace/slam_in_autonomous_driving
 
-# Compile g2o first
+# Compile g2o
 cd ~/workspace/slam_in_autonomous_driving/thirdparty/g2o/
-cmake .
+mkdir build && cd build
+cmake ..
 make -j8 
+make install
+ldconfig
 
 # Compile the source code
 cd ~/workspace/slam_in_autonomous_driving
@@ -36,4 +39,4 @@ mkdir build && cd build
 cmake ..
 make -j8
 ```
-<a href="url"><img src="./images/ubuntu.png" width="600"></a>  
+<a href="url"><img src="./images/ubuntu.png" width="700"></a>