I hope the screen reader software doesn't read 'link' when it reads the title

## Feature request

I hope to add a feature that the md file title does not read out the link.

#### What problem does this feature solve?

Friendly for some people who use screen reader software

#### What does the proposed API look like?

just like

```
window.$docsify = {
readLink: false,
}
```

#### How should this be implemented in your opinion?

I don't think this should be hard to implement, e.g. generating html for md files without a tag.

I'm afraid I can't.