Add debugging-snapshot-enabled back

Author: lisenet

cluster-autoscaler/FAQ.md

@@ -788,6 +788,7 @@ The following startup parameters are supported for cluster autoscaler:
 | `feature-gates` | A set of key=value pairs that describe feature gates for alpha/experimental features. | ""
 | `cordon-node-before-terminating` | Should CA cordon nodes before terminating during downscale process | false
 | `record-duplicated-events` | Enable the autoscaler to print duplicated events within a 5 minute window. | false
+| `debugging-snapshot-enabled` | Whether the debugging snapshot of cluster autoscaler feature is enabled. | false
 | `node-delete-delay-after-taint` | How long to wait before deleting a node after tainting it. | 5 seconds
 
 # Troubleshooting: