Docs: fix info box in ImplementingUndoHistory (reduxjs#4075)

StefanBRas · web-flow · commit d97a4a3e6641 · 2021-04-22T09:44:10.000-04:00
diff --git a/docs/recipes/ImplementingUndoHistory.md b/docs/recipes/ImplementingUndoHistory.md
@@ -6,7 +6,7 @@ hide_title: true
 
 # Implementing Undo History
 
-:::Prerequisites
+:::important Prerequisites
 
 - Completion of the ["Redux Fundamentals" tutorial](../tutorials/fundamentals/part-1-overview.md)
 - Understanding of ["reducer composition"](../tutorials/fundamentals/part-3-state-actions-reducers.md#splitting-reducers)
