zero-downtime-restart: improve explanation about temporal buffer

Signed-off-by: Daijiro Fukuda <fukuda@clear-code.com>
Co-authored-by: Kentaro Hayashi <kenhys@gmail.com>

Author: daipom

deployment/zero-downtime-restart.md

@@ -33,14 +33,12 @@ You can use this feature in the following ways.
    * Launch new workers with [Source Only Mode](source-only-mode.md).
      * In addition to source-only mode, further limit the starting pluings to only those that support this feature.
      * Data received by the new workers are stored in the temporary buffer of source-only mode.
+     * For details on the temporary buffer, see [Source ONLY MODE - Temporary file buffer](source-only-mode.md#temporary-file-buffer).
    * Send `SIGTERM` to the old supervisor after `10s` delay.
 5. The old supervisor stops and sends `SIGWINCH` to the new one.
 6. The new workers starts to run fully.
    * The temporary buffer of source-only mode starts to load.
 
-You can configure the temporary buffer.
-See [Source Only Mode](source-only-mode.md) for details.
-
 ## Plugins: how to support this feature
 
 See [How to Write Input Plugin - zero_downtime_restart_ready?](../plugin-development/api-plugin-input.md#zero_downtime_restart_ready).