samples: background-workers config example

samples/knot.full.conf

@@ -42,6 +42,11 @@ system {
   # Default: unset (auto-estimates optimal value from the number of online CPUs)
   # workers 3;
 
+  # Number of background workers
+  # This option is used to set number of threads used to execute background
+  # operations (e.g., zone loading, zone signing, XFR zone updates, ...)
+  # Default: unset (auto-estimates optimal value from the number of online CPUs)
+  # background-workers 4;
   # User for running server
   # May also specify user.group (e.g. knot.users)
   # user knot.users;