Geo: Add tuning settings

doc/administration/geo/replication/tuning.md

@@ -7,18 +7,25 @@ type: howto
 
 # Tuning Geo **(PREMIUM ONLY)**
 
-## Changing the sync capacity values
+## Changing the sync/verification capacity values
 
 In the Geo admin page at **Admin Area > Geo** (`/admin/geo/nodes`),
 there are several variables that can be tuned to improve performance of Geo:
 
-- Repository sync capacity.
-- File sync capacity.
+- Repository sync capacity
+- File sync capacity
+- Container repositories sync capacity
+- Verification capacity
 
-Increasing these values will increase the number of jobs that are scheduled.
+Increasing capacity values will increase the number of jobs that are scheduled.
 However, this may not lead to more downloads in parallel unless the number of
 available Sidekiq threads is also increased. For example, if repository sync
 capacity is increased from 25 to 50, you may also want to increase the number
 of Sidekiq threads from 25 to 50. See the
 [Sidekiq concurrency documentation](../../operations/extra_sidekiq_processes.md#number-of-threads)
 for more details.
+
+## Repository re-verification
+
+See
+[Automatic background verification](../disaster_recovery/background_verification.md).