Multiple Launch Files in Visual Studio Code

Although the question is about multiple configurations for a single folder, just want to mention the alternative: multiple folders in a single workspace, each with their own launch.json.

One way is to just copy the .vscode/launch.json file to the other folder and edit it. The desired configuration can be picked up or edited from the drop-down to the right of the "Start Debugging" (Green "play") button.

VSCode supports only one launch.json, but you can have multiple launch configurations inside one launch.json. The example at https://code.visualstudio.com/Docs/debugging has 3 different launch configurations. You can specify any amount, and choose the active one using a drop down in the debug view.