[Bug] markdown to document newline & image in paragraph

### Bug Description

When converting a document to markdown we have this
```
line1
line2

line3
```

After creating a document from markdown
Appflowy editor renders
```
line1
line2
line3
```

### How to Reproduce

create a new editor from markdown with the previous content.
- Newline is skipped.
- Images are skipped

### Expected Behavior

The empty line should be rendered
THe image should be rendered

Note : the newline is correctly rendered by markdown renderer when exporting markdown from editor.

### Operating System

android, ios

### AppFlowy Editor Version(s)

latest

### Screenshots

_No response_

### Additional Context

_No response_