Update cluster iterator docs

Signed-off-by: Björn Svensson <[email protected]>

docs/cluster.md

@@ -331,26 +331,25 @@ For subsequent calls it will return `VALKEY_ERR`.
 ### Cluster node iterator
 
 A `valkeyClusterNodeIterator` can be used to iterate on all known master nodes in a cluster context.
-First it needs to be initiated using `valkeyClusterInitNodeIterator` and then you can repeatedly call `valkeyClusterNodeNext` to get the next node from the iterator.
+First it needs to be allocated using `valkeyClusterGetNodeIterator` and then you can repeatedly call `valkeyClusterNodeNext` to get the next node from the iterator.
 
 ```c
-valkeyClusterNodeIterator ni;
-valkeyClusterInitNodeIterator(&ni, cc);
-
+valkeyClusterNodeIterator ni = valkeyClusterGetNodeIterator(cc);
 valkeyClusterNode *node;
 while ((node = valkeyClusterNodeNext(&ni)) != NULL) {
    valkeyReply *reply = valkeyClusterCommandToNode(cc, node, "DBSIZE");
    // Handle reply..
 }
+valkeyClusterReleaseNodeIterator(ni);
 ```
 
 The iterator will handle changes due to slot map updates by restarting the iteration, but on the new set of master nodes.
 There is no bookkeeping for already iterated nodes when a restart is triggered, which means that a node can be iterated over more than once depending on when the slot map update happened and the change of cluster nodes.
 
 Note that when `valkeyClusterCommandToNode` is called, a slot map update can happen if it has been scheduled by the previous command, for example if the previous call to `valkeyClusterCommandToNode` timed out or the node wasn't reachable.
 
-To detect when the slot map has been updated, you can check if the slot map version (`iter.route_version`) is equal to the current cluster context's slot map version (`cc->route_version`).
-If it isn't, it means that the slot map has been updated and the iterator will restart itself at the next call to `valkeyClusterNodeNext`.
+To detect when the slot map has been updated, you can check if the slot map version has changed during the iteration (see `cc->route_version`).
+A change means that the slot map has been updated and the iterator will restart itself at the next call to `valkeyClusterNodeNext`.
 
 Another way to detect that the slot map has been updated is to [register an event callback](#events-per-cluster-context) and look for the event `VALKEYCLUSTER_EVENT_SLOTMAP_UPDATED`.