docs: Document the flow between analytical mode and replication (#1413)

* docs: Analytical+replication flow

* Update pages/clustering/replication.mdx

---------

Co-authored-by: Matea Pesic <[email protected]>

Author: as51340

pages/clustering/replication.mdx

@@ -24,6 +24,8 @@ then the REPLICA instances.
 Data replication currently **works only in the in-memory transactional [storage
 mode](/fundamentals/storage-memory-usage)**.
 
+If you're using in-memory analytical storage mode for the fast import, please first import your data, then set up the replication.
+
 </Callout>
 
 When distributing data across several instances, Memgraph uses replication to