Modify text summarization taskflow doc

[LazyFyh]

PR types

Modify taskflow.md

PR changes

Docs

Description

修改了文本摘要taskflow的文档，增加了参数说明

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[paddle-bot]

Thanks for your contribution!

[wawltor]

LGTM

[github-actions]

This Pull Request is stale because it has been open for 60 days with no activity. 当前Pull Request 60天内无活动，被标记为stale。

[github-actions]

This Pull Request is stale because it has been open for 60 days with no activity. 当前Pull Request 60天内无活动，被标记为stale。

[github-actions]

This Pull Request is stale because it has been open for 60 days with no activity. 当前Pull Request 60天内无活动，被标记为stale。

[github-actions]

This Pull Request is stale because it has been open for 60 days with no activity. 当前Pull Request 60天内无活动，被标记为stale。

[paddle-bot]

Automatically closed by Paddle-bot.