chore(changelog): document challenge-form translation implementation (#503)

Author: Alberto Basanta

CHANGELOG.md

@@ -10,6 +10,7 @@ and this project adheres to
 - Fixed missing braces in en.json and es.json (#492)
 - Refactored challenge-form service and component to load tags based on selected language (#470)
 - Visual refactor of icons in challenge-header (rocket icon, hover effects, tooltip, and layout reorder) (#471)
+- Added translation support to challenge-form: replaced static text with translation keys and updated language JSONs (#503)
 
 ### [ita-challenges-frontend-3.1.35-RELEASE] - 2025-05-28