Fix broken ETL and Map Reduce urls (PrefectHQ#4967)

felipewhitaker · web-flow · commit 2cd13929c770 · 2021-09-16T11:00:33.000-05:00
The links for the tutorials for `ETL` and `Map Reduce` on the top of the page are broken. 
- `ETL` tutorial exists, and the code in this page is the same as the one in the updated link. It appears that it had been moved to `advanced tutorials`.
- `Map Reduce` tutorial could not be found, but the code in this page resembles the one in the `reduce` part of the `mapping` concept page.
diff --git a/docs/orchestration/recipes/multi_flow_storage.md b/docs/orchestration/recipes/multi_flow_storage.md
@@ -1,7 +1,7 @@
 
 # Multi Flow Storage
 
-This recipe is for storing multiple flows inside a single [Docker storage object](/api/latest/storage.html#docker). This is useful when you have a suite of flows that registers off of a CI/CD process or if you want to reduce the number of images stored in a container registry. For this recipe we are going to put two example flows — [ETL](/core/examples/etl.html) and [Map Reduce](/core/examples/map_reduce.html) — inside of the same Docker storage object.
+This recipe is for storing multiple flows inside a single [Docker storage object](/api/latest/storage.html#docker). This is useful when you have a suite of flows that registers off of a CI/CD process or if you want to reduce the number of images stored in a container registry. For this recipe we are going to put two example flows — [ETL](/core/advanced_tutorials/etl.html) and [Map Reduce](/core/concepts/mapping.html#reduce) — inside of the same Docker storage object.
 
 [[toc]]
 
