Support for custom link transforms (overriding md.link)

[jsakas]

In notion, if you use the @ to reference a page inside of a paragraph, it gets added as a mention inside of the paragraph rich_text object. The default link transformation is hard-coded to the notion.so/:page_id link. This makes it difficult to use this package for generating content for static sites that are outside of Notion. For example, we're using Notion to render static pages into our Astro site (think CMS)

Proposal: introduce NotionToMarkdown.linkTransformer and NotionToMarkdown.setLinkTransformer which wraps md.link.

I will add a PR for your review.

[souvikinator]

@jsakas, thanks for raising the issue and the PR. This is a limitation in v3. In v4-alpha we do have annotation transformers which handle links. Here is link to the docs

pls share your thoughts