docs(mutations): Update community resources (TanStack#2781)

Author: TkDodo

docs/src/pages/community/tkdodos-blog.md

@@ -49,3 +49,7 @@ React Query maintainer [TkDodo](https://twitter.com/tkdodo) has a series of blog
 ## [#11: React Query Error Handling](https://tkdodo.eu/blog/react-query-error-handling)
 
 > Handling errors is an integral part of working with asynchronous data, especially data fetching. We have to face it: Not all requests will be successful, and not all Promises will be fulfilled. This blog post describes various ways of coping with errors in React Query, such as the error property, using Error Boundaries or onError callbacks, so that you can prepare your application for the cases when "Something went wrong". [Read more...](https://tkdodo.eu/blog/react-query-error-handling)
+
+## [#12: Mastering Mutations in React Query](https://tkdodo.eu/blog/mastering-mutations-in-react-query)
+
+> Mutation are the important, second part necessary to work with server data - for situations where you need to update it. This blog post covers what mutations are and how they are different from queries. You'll learn the difference between `mutate` and `mutateAsync` as well as how you can tie queries and mutations together. [Read more...](https://tkdodo.eu/blog/mastering-mutations-in-react-query)

docs/src/pages/guides/mutations.md

@@ -256,3 +256,8 @@ hydrate(queryClient, state)
 // Resume the paused mutations:
 queryClient.resumePausedMutations()
 ```
+
+## Further reading
+
+For more information about mutations, have a look at [#12: Mastering Mutations in React Query](../community/tkdodos-blog#12-mastering-mutations-in-react-query) from
+the Community Resources.