In many occasions some docs authors want to generate dynamic pages based on the metadata of other pages. Imagine that you describe one property/method of your library per file in the /docs/reference/{propname}.mdx
In this MDX you use the metadata to describe some basics of your property (type, default value etc.) From this folder you want to be able to generate an overview table listing all properties of your library. Take https://datatables.net/reference/option/ as a reference on that.
Currently Docusaurus does not provide a way to query all docs pages from the /docs/reference folder and access their metadata for dynamically generating content on a /docs/reference/index.mdx