feat(ai): respond using same language as question

supabase/functions/ai-docs/index.ts

@@ -198,6 +198,9 @@ serve(async (req) => {
           ${oneLine`
             - Prefer splitting your response into multiple paragraphs.
           `}
+          ${oneLine`
+            - Respond using the same language as the question.
+          `}
           ${oneLine`
             - Output as markdown.
           `}