pd-control: add description for `scheduler config evict-leader-schedu…

…ler` (pingcap#17968) (pingcap#18077)

pd-control.md

@@ -686,12 +686,14 @@ Use this command to view and control the scheduling policy.
 Usage:
 
 ```bash
->> scheduler show                                 // Display all schedulers
->> scheduler add grant-leader-scheduler 1         // Schedule all the leaders of the Regions on store 1 to store 1
->> scheduler add evict-leader-scheduler 1         // Move all the Region leaders on store 1 out
->> scheduler config evict-leader-scheduler        // Display the stores in which the scheduler is located since v4.0.0
->> scheduler add shuffle-leader-scheduler         // Randomly exchange the leader on different stores
->> scheduler add shuffle-region-scheduler         // Randomly scheduling the Regions on different stores
+>> scheduler show                                          // Display all schedulers
+>> scheduler add grant-leader-scheduler 1                  // Schedule all the leaders of the Regions on store 1 to store 1
+>> scheduler add evict-leader-scheduler 1                  // Move all the Region leaders on store 1 out
+>> scheduler config evict-leader-scheduler                 // Display the stores in which the scheduler is located since v4.0.0
+>> scheduler config evict-leader-scheduler add-store 2     // Add leader eviction scheduling for store 2
+>> scheduler config evict-leader-scheduler delete-store 2  // Remove leader eviction scheduling for store 2
+>> scheduler add shuffle-leader-scheduler                  // Randomly exchange the leader on different stores
+>> scheduler add shuffle-region-scheduler                  // Randomly schedule the Regions on different stores
 >> scheduler add evict-slow-store-scheduler       // When there is one and only one slow store, evict all Region leaders of that store
 >> scheduler remove grant-leader-scheduler-1      // Remove the corresponding scheduler, and `-1` corresponds to the store ID
 >> scheduler pause balance-region-scheduler 10    // Pause the balance-region scheduler for 10 seconds
@@ -807,6 +809,24 @@ Usage:
     >> scheduler config balance-hot-region-scheduler set enable-for-tiflash true
     ```
 
+### `scheduler config evict-leader-scheduler`
+
+Use this command to view and manage the configuration of the `evict-leader-scheduler`.
+
+- When an `evict-leader-scheduler` already exists, use the `add-store` subcommand to add leader eviction scheduling for the specified store:
+
+    ```bash
+    scheduler config evict-leader-scheduler add-store 2       // Add leader eviction scheduling for store 2
+    ```
+
+- When an `evict-leader-scheduler` already exists, use the `delete-store` subcommand to remove leader eviction scheduling for the specified store:
+
+    ```bash
+    scheduler config evict-leader-scheduler delete-store 2    // Remove leader eviction scheduling for store 2
+    ```
+
+    If all store configurations of an `evict-leader-scheduler` are removed, the scheduler itself is automatically removed.
+
 ### `store [delete | label | weight | remove-tombstone | limit ] <store_id>  [--jq="<query string>"]`
 
 Use this command to view the store information or remove a specified store. For a jq formatted output, see [jq-formatted-json-output-usage](#jq-formatted-json-output-usage).