The steps to build a new extension for Azure Data Studio are in this repository. You should be able to follow along using the notebooks here - start with 1_YoAzdata.ipynb and step through from there. They can be viewed in Github, but we recommend using Azure Data Studio to follow along as it includes clickable actions.
SQLvariant/msbuild_ads_demo
Contributing and Building extensions for Azure Data Studio session at Microsoft Build.
Jupyter NotebookMIT