docs(strm): Local Mode modify to Without Url & Add save local strm

[sevxn007]

Description / 描述

Motivation and Context / 背景

添加保存本地strm说明、本地模式字段修改为不携带url前缀

Checklist / 检查清单

• I have read the CONTRIBUTING document.
  我已阅读 CONTRIBUTING 文档。
• I have formatted my code or documentation with prettier or other appropriate formatter.
  我已使用 prettier 或其他适当的格式化工具格式化提交的代码或文档。
• I have updated all supported languages (including Chinese and English) for documentation. (If it's needed)
  我已为所有支持语言（包括中文和英文）更新文档内容。 (若适用)
• I have verified that the written documentation or code is properly formatted, with no syntax errors, spelling mistakes.
  我已确认编写的文档或代码格式正确, 无语法错误, 拼写错误。
• I have updated the repository accordingly (If it's needed).
  我已相应更新了相关仓库（若适用）。
  • OpenList #1483
  • OpenList-Frontend #XXXX