Added link to python io unicode warning issue.

Shell-aliases.md

@@ -33,15 +33,15 @@ Put this in your Powershell `$PROFILE` on Windows:
 iex "$(thefuck --alias)"
 ```
 
-To overcome Python unicode warnings on your unicode Powershell console:
-```
+To overcome Python unicode [warning](https://github.com/nvbn/thefuck/issues/514) on your unicode Powershell console:
+```powershell
 c:\python3\lib\site-packages\win_unicode_console\__init__.py:31: RuntimeWarning: sys.stdin.encoding == 'utf-8', whereas sys.stdout.encoding == 'ascii', readline hook consumer may assume they are the same
   readline_hook.enable(use_pyreadline=use_pyreadline)
 ```
 
 Add this line **before** the line above in your Powershell `$PROFILE` on Windows:
 
-```
+```powershell
 $env:PYTHONIOENCODING="utf-8"
 ```