update docs

Signed-off-by: NAnnie_wang <annie.wangli@huawei.com>

en/device-dev/faqs/faqs-building.md

@@ -94,17 +94,15 @@
   
 - **Solution**
   
-  1. Run the following command to query the Python version:
-     
-```
+    1. Run the following command to query the Python version:
+       
+      ```
       python3 --version
-```
+      ```
   2. Ensure that Python 3.7 or later is installed, and then run the following command to install pycryptodome:
      
       ```
       sudo pip3 install pycryptodome
-      ```
-
 
 ### "xx.sh : xx unexpected operator" Displayed During the Build Process
 
@@ -145,17 +143,16 @@
 
 - **Solution**
   
-
   Method 1: Run the **pip3 install six** command to install **six** online.
-
-  Method 2: Offline installation
-
-  Download the installation package from [PyPI](https://pypi.org/project/six/#files).
-
-  ![en-us_image_0000001251276115](figures/en-us_image_0000001251276115.png)
-
-  Save the source code to the Linux server and run the **pip3 install six-1.14.0-py2.py3-none-any.whl** command to install **six**.
-
+  
+  Method 2: Install **six** offline.
+  
+    a) Download the installation package from [PyPI](https://pypi.org/project/six/#files).
+  
+       ![en-us_image_0000001251276115](figures/en-us_image_0000001251276115.png)
+  
+     b) Save the source code to the Linux server and run the **pip3 install six-1.14.0-py2.py3-none-any.whl** command to install **six**.
+  
   After the preceding installation is complete, rebuild an environment.