To use typescript, you need to install the faucet-pipeline-typescript package. The configuration is an array of bundles you want to create. Each entry of the array is an object with at least two keys: source is the file that should be compiled, and target is the file that should be created (the path is, of course, modified a little when you use fingerprinting). You also need to set typescript to true for the bundles that should be compiled with TypeScript:

module.exports = {
    js: [{
        source: "./src/index.ts",
        target: "./dist/bundle.js",
        typescript: true