Add translations in French and Dutch

[alexnuttinck]

This pull request adds new translations in both French and Dutch.

[sventorben]

@alexnuttinck, thanks a lot for your contribution and for adding these new translations. It’s always great to see the project become more accessible for more users!

Before I can merge the PR, could you please sign your commits according to the contribution guidelines? This is just a small housekeeping requirement applied to all contributions. You’ll find the instructions here: https://github.com/sventorben/keycloak-home-idp-discovery/blob/main/CONTRIBUTING.md#commit-signing-requirement

Once the commits are signed, feel free to push an update to the same branch and the PR will update automatically.

Thanks again for taking the time to contribute; it’s very much appreciated!

[alexnuttinck]

Thank you @sventorben. The GitHub-verified signature was missing, it has now been added.