* Add primary shard balancing documentation Signed-off-by: Fanit Kolchina <[email protected]> * Adds default value Signed-off-by: Fanit Kolchina <[email protected]> * Update _api-reference/cluster-api/cluster-settings.md Co-authored-by: Nathan Bower <[email protected]> --------- Signed-off-by: Fanit Kolchina <[email protected]> Co-authored-by: Nathan Bower <[email protected]>