The ContentLayer of Stackbit has not been maintained for a while.
Although there are many alternatives, such as next/mdx, I think the output structure of Contentlayer is appealing.
So I made a simple and lightweight version of Contentlayer.
You need archivelayer.config.js in your base directory. See tests/next-test/archivelayer.config.js
To compile all the markdown / mdx files, execute a script like the following "archivelayer dev".
If you want the file to reflect edits, execute a script like the following "concurrently \"archivelayer dev\" \"next dev -p 4000\""
Then, archivelayer compiles the file and saves in .archivelayer/generated.
It is an auto generated module you can import.