Upgrading to 1.0.0

Already a mkdocs-static-i18n plugin user? Thank you!

The plugin's configuration changed quite a lot since the previous version so I wrote a migration script that you just need to point to your current mkdocs.yml file and that will output the desired v1.0.0 YAML configuration for you!

$ python config_update_to_v1.py /path/to/mkdocs.yml