docs: The default for pr_description.final_update_message is true.

Author: Yunosuke Yamada

docs/docs/tools/describe.md

@@ -118,7 +118,7 @@ This option is enabled by default via the `pr_description.enable_pr_diagram` par
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         <td><b>final_update_message</b></td>
-        <td>If set to true, it will add a comment message [`PR Description updated to latest commit...`](https://github.com/Codium-ai/pr-agent/pull/499#issuecomment-1837412176) after finishing calling `/describe`. Default is false.</td>
+        <td>If set to true, it will add a comment message [`PR Description updated to latest commit...`](https://github.com/Codium-ai/pr-agent/pull/499#issuecomment-1837412176) after finishing calling `/describe`. Default is true.</td>
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         <td><b>enable_semantic_files_types</b></td>