Update booking form and environment configuration

- Update .env.example with map coordinates (ADDRESS_LATITUDE/LONGITUDE)
- Update ADDRESS_STREET to Liebigstr. 15 and postal code to 24145
- Document GPS coordinates for interactive map feature in legal page

src/client/components/booking-form.tsx

@@ -342,7 +342,7 @@ export function BookingForm() {
             onChange={(e) => setNotes(e.target.value)}
             rows={3}
             className="w-full p-3 border border-gray-300 rounded-md focus:ring-2 focus:ring-pink-500 focus:border-pink-500"
-            placeholder="Besondere Wünsche oder Informationen..."
+            placeholder="Besondere Wünsche oder Informationen, Allergien, etc..."
           />
         </div>