docs: Add --yes flag to svc exec docs. (#2761)

<!-- Provide summary of changes -->
Adds the --yes flag to `copilot svc exec` docs.

<!-- Issue number, if available. E.g. "Fixes #31", "Addresses #42, 77" -->
Fixes #2760

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site/content/docs/commands/svc-exec.en.md

@@ -15,6 +15,7 @@ $ copilot svc exec
   -h, --help               help for exec
   -n, --name string        Name of the service, job, or task group.
       --task-id string     Optional. ID of the task you want to exec in.
+      --yes                Optional. Whether to update the Session Manager Plugin.
 ```
 
 ## Examples

site/content/docs/commands/svc-exec.ja.md

@@ -15,6 +15,7 @@ $ copilot svc exec
   -h, --help               help for exec
   -n, --name string        Name of the service, job, or task group.
       --task-id string     Optional. ID of the task you want to exec in.
+      --yes                Optional. Whether to update the Session Manager Plugin.
 ```
 
 ## 実行例