Ignore docs while generating po files as well

scripts/update-locales

 #!/bin/sh
 
-./manage.py makemessages -a -i 'repos/*'
-./manage.py makemessages -a -i 'repos/*' -d djangojs
+./manage.py makemessages -a -i 'repos/*' -i 'docs/*'
+./manage.py makemessages -a -i 'repos/*' -i 'docs/*' -d djangojs