Improved local shell snippet rendering

knowledge base/python.md

@@ -59,14 +59,14 @@ if __name__ == "__main__":
     serve(app, host="0.0.0.0", port=8080)
 ```
 
-```shell
+```sh
 pip install flask waitress
 python hello.py
 ```
 
 ## Maintenance
 
-```shell
+```sh
 # generate a list of all outdated packages
 pip list --outdated