Pontoon: Update French (fr) localization of Nimbus Experiments

Co-authored-by: Théo Chevalier <theochevalier@pm.me>

Author: TheoChevalier

fr/subset/ask_windows_mac_desktop_early_day_profiles_about_their_firefox_use_case_2024.ftl

@@ -6,4 +6,18 @@
 ## Branch: treatment-a
 
 # The title of a popup asking the user about their Firefox usage by answering a short survey
-survey-title = Pourquoi utilisez-vous Firefox ?
+survey-title = À quoi vous sert Firefox ?
+# Label for the button that submits the user's response to the survey question
+submit-button-label = Envoyer
+# Text for privacy notice link
+privacy-notice-label = Politique de confidentialité
+# Work option for Firefox usage
+survey-checkbox-work-label = Travail
+# School option for Firefox usage
+survey-checkbox-school-label = École
+# Personal option for Firefox usage
+survey-checkbox-personal-label = Personnel
+# Other option for Firefox usage
+survey-checkbox-other-label = Autre
+# Text displayed in a thank-you toast notification that appears briefly after the user submits their survey response
+thanks-toast-title = Merci de votre retour !