feat: add German descriptions and titles to Luxembourg source records

[HirenGajjar]

Closes #20

Adds title_de and description_de to both existing Luxembourg source records. Also adds de to the languages array of guichet-death-life-event.yaml where it was missing, and notes the German-language URLs for both pages.

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Changes

data/sources/lu/guichet-death-life-event.yaml

• Added title_de: "Todesfall eines Angehörigen"
• Added description_de: German translation of the English description
• Added de to languages array (Guichet page has a verified German version)
• Updated notes with German URL: https://guichet.public.lu/de/citoyens/life-event/famille-education/deces-proche.html

data/sources/lu/guichet-death-certificate.yaml

• Added title_de: "Sterbeurkunde"
• Added description_de: German translation of the English description
• de already present in languages ✅
• Updated notes with German URL: https://guichet.public.lu/de/citoyens/justice/certificats-copies-actes-casier-judicaire/certificats-copies-actes/acte-deces.html

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Translation note

German translations are machine-assisted. Native speaker review welcome — flagging here as good practice for a bereavement context where precise language matters.

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Verified

• python3 scripts/validate.py — passes (10 data files)
• Trailing newlines present on both files
• 2 files changed, 7 insertions, 2 deletions

[TommiLindfors]

Merged! Good call on flagging the translations as machine-assisted. We appreciate the transparency — native speaker review is definitely welcome for bereavement context. Twelve merged PRs now.