Add a VSCode page here:
https://github.com/10gen/devtools-internal-docs/tree/main/technical

That links to the VSCode docs:
https://github.com/mongodb-js/vscode/blob/main/CONTRIBUTING.md#releases 

In the VSCode docs add a step with a link to the testing matrix and describe the process.

Testing matrix: https://docs.google.com/spreadsheets/d/1014WyX-WPMfZTj6qVyYDA1JowGCFNCOQGgEhIA0O0bs/edit#gid=0