修正 烧录系统.

Signed-off-by: lion.chan <cy187lion@sina.com>

Software/System/RaspberryPi/Raspberry_Pi_4B_安装_Ubuntu_Desktop_21.04.md

@@ -21,21 +21,17 @@ sudo pacman -S rpi-imager
 
 ![Operating System](./img/Raspberry_Pi_4B_安装_Ubuntu_Desktop_21.04/001.png)
 
-![Other general purpose OS](./img/Raspberry_Pi_4B_安装_Ubuntu_Desktop_21.04/002.png)
+![Use custom](./img/Raspberry_Pi_4B_安装_Ubuntu_Desktop_21.04/002.png)
 
-![Ubuntu](./img/Raspberry_Pi_4B_安装_Ubuntu_Desktop_21.04/003.png)
+![Storage](./img/Raspberry_Pi_4B_安装_Ubuntu_Desktop_21.04/003.png)
 
-![Ubuntu Desktop 21.04(RPi 4/400)](./img/Raspberry_Pi_4B_安装_Ubuntu_Desktop_21.04/004.png)
+![选择 TF 卡](./img/Raspberry_Pi_4B_安装_Ubuntu_Desktop_21.04/004.png)
 
-![Storage](./img/Raspberry_Pi_4B_安装_Ubuntu_Desktop_21.04/005.png)
+![WRITE](./img/Raspberry_Pi_4B_安装_Ubuntu_Desktop_21.04/005.png)
 
-![选择 TF 卡](./img/Raspberry_Pi_4B_安装_Ubuntu_Desktop_21.04/006.png)
+![确认警告](./img/Raspberry_Pi_4B_安装_Ubuntu_Desktop_21.04/006.png)
 
-![WRITE](./img/Raspberry_Pi_4B_安装_Ubuntu_Desktop_21.04/007.png)
-
-![确认警告](./img/Raspberry_Pi_4B_安装_Ubuntu_Desktop_21.04/008.png)
-
-![写入过程](./img/Raspberry_Pi_4B_安装_Ubuntu_Desktop_21.04/009.png)
+![写入过程](./img/Raspberry_Pi_4B_安装_Ubuntu_Desktop_21.04/007.png)
 
 ## 外部参考资料