docs: update json-mapper.md

docs/docs/json-mapper.md

@@ -262,7 +262,7 @@ and import the mapper in your application.
 <<< @/../packages/specs/json-mapper/src/components/DateMapper.spec.ts [Vitest]
 :::
 
-::: warn
+::: warning
 Ts.ED doesn't transform Date to date format or hours format because it depends on each project guidelines.
 
 But you can easily implement a Date mapper for each format with the Date API or moment: