doc/rados: edit balancer.rst

Edit doc/rados/operations/balancer.rst. Follow up on matters raised in
ceph#63530. Make the English clearer.

Signed-off-by: Zac Dover <[email protected]>
(cherry picked from commit 7bf5196)

Author: zdover23

doc/rados/operations/balancer.rst

@@ -60,11 +60,11 @@ of the following form:
 A larger value may increase the speed of cluster balancing / convergence
 at the potential cost of greater impact on client operations.
 
-There is a separate setting for how uniform the distribution of PGs
-must be for the module to consider adequately balanced.
-At the time of writing this value defaults to ``5``, which means that
-if a given OSD's PG replicas vary by five or fewer above or below the
-cluster's average, it will be considered sufficiently balanced.
+There is a separate setting for how uniform the distribution of PGs must be for
+the module to consider the cluster adequately balanced.  At the time of writing
+(June 2025), this value defaults to ``5``, which means that if a given OSD's PG
+replicas vary by five or fewer above or below the cluster's average, it will be
+considered sufficiently balanced.
 
 This value of PG replicas / shards (as distinct from logical PGs) is reported
 by the ``ceph osd df`` command under the ``PGS`` column and the variance