docs(query-keys): clarify query key refetching (#5653)

* docs(query-keys): clarify query key refetching 

Update the query-key documentation to note that changing data included in a query key will automatically refetch the query data.

It took me a long time to find this information, and I expected to find it here. I consulted with another engineer on our team, and they agreed that they would expect to see it stated more clearly here. So we felt this addition would be helpful.

* Update docs/react/guides/query-keys.md

* Update docs/react/guides/query-keys.md

---------

Co-authored-by: Dominik Dorfmeister <office@dorfmeister.cc>

Author: meatnordrink

docs/react/guides/query-keys.md

@@ -90,6 +90,8 @@ function Todos({ todoId }) {
 ```
 
 [//]: # 'Example5'
+
+Note that query keys act as dependencies for your query functions. Adding dependent variables to your query key will ensure that queries are cached independently, and that any time a variable changes, *queries will be refetched automatically (depending on your `staleTime` settings).* (See the [exhaustive-deps](../eslint/exhaustive-deps) section for more information and examples.)
 [//]: # 'Materials'
 
 ## Further reading