Change dashbord language to french

The custom dir was in the very old legacy branch and the info on https://github.com/COCOPi/cockpit-i18n is outdated. There is a new repo GitHub - agentejo/cockpit-i18n instead - without language files - may be updated in the future…

Steps to translate:

  1. Create a dummy language file:
  1. translate
  2. Put your language file(s) in path/to/cockpit/config/cockpit/i18n/fr.php
  3. edit config.yaml:
i18n : fr     # set default/backend lang to French
languages:    # optional: make entries multilingual, "fr" is default now
  en: English
  de: Deutsch
  1. If you still don’t see any change, make sure, you chose the correct language in your account settings
  2. optional: If your language file is complete, file a pull request in GitHub - agentejo/cockpit-i18n