website: update documention for the plan rejection tracker

website/content/docs/configuration/server.mdx

@@ -254,8 +254,8 @@ more details.
 - `node_threshold` `(int: 100)` - The number of plan rejections for a node
   within the `node_window` to trigger a client to be set as ineligible.
 
-- `node_window` `(int: "5m")` - The time window for when plan rejections for a
-  node should be considered.
+- `node_window` `(string: "5m")` - The time window for when plan rejections for
+  a node should be considered.
 
 If you observe too many false positives (clients being marked as ineligible
 even if they don't present any problem) you may want to increase

website/content/docs/operations/monitoring-nomad.mdx

@@ -149,10 +149,15 @@ While it is possible for these log lines to occur infrequently due to normal
 cluster conditions, they should not appear repeatedly and prevent the job from
 eventually running (look up the evaluation ID logged to find the job).
 
-Nomad tracks the history of plan rejections per client and will mark it as
-ineligible for scheduling if the number of rejections goes above a given
-threshold within a time window. When this happens, the following node event is
-registered:
+#### Plan rejection tracker
+
+Nomad provides a mechanism to track the history of plan rejections per client
+and mark them as ineligible if the number goes above a given threshold within a
+time window. This functionality can be enabled using the
+[`plan_rejection_tracker`] server configuration.
+
+When a node is marked as ineligible due to excessive plan rejections, the
+following node event is registered:
 
 ```
 Node marked as ineligible for scheduling due to multiple plan rejections