Add export markdown files

[liupengzhouyi]

Is your feature request related to a problem?

I want to used my infomation on Typora.

Describe the solution you'd like

├── 2023
    ├── 1
    │ ├── 23
    │ │ └── 001.md
    │ ├── 30
    │ │ └── 001.md
    │ └── 31
    │   └── 001.md
    │ 
    ├── 2
      ├── 23
      │ └── 001.md
      ├── 25
      │ └── 001.md
      └── 26
        └── 001.md

Additional context

No response

[Zeng1998]

It is not a general/common usage. Please handle the database by yourself to get the information you need.

[Zeng1998]

Discuss in #778 .