Warn users that changing the store format also changes the built-in _id property and elementID

Author: renetapopova

modules/ROOT/pages/database-internals/store-formats.adoc

@@ -118,6 +118,12 @@ CREATE DATABASE blockdb OPTIONS {storeFormat: 'block'}
 Starting from 5.23, `block` format is the preferred format for Enterprise Edition due to its superior performance and scalability.
 Therefore, migrating all databases to `block` format is recommended to ensure optimal performance.
 
+[NOTE]
+====
+Be aware that changing the store format changes the built-in _id property and elementID of nodes and relationships.
+This is because _id represents the elements physical location in the store file.
+====
+
 Changing the store format is an IO-intensive offline operation, which re-writes all data in the new format.
 Therefore, it requires that: