To export your data from Sanity.io into markdown files, you'll need to create a script that fetches the data from Sanity and then converts it into the desired markdown format. You can use Node.js for this task. The following steps outline the process:
Install required dependencies: First, make sure you have Node.js installed on your computer. Then, create a new folder for your project and initialize it with npm:
mkdir sanity-export
cd sanity-export
npm init -y