Add shebang to output

cli/rollup.config.js

@@ -9,7 +9,10 @@ export default {
   output: {
     dir: "build",
     format: "cjs",
-    assetFileNames: "[name]-[hash][extname]"
+    assetFileNames: "[name]-[hash][extname]",
+    // This is needed so the resulting `index.js` can be
+    // executed by `npx`.
+    banner: "#!/usr/bin/env node"
   },
   plugins: [
     resolve(),

cli/src/index.js

@@ -146,6 +146,7 @@ async function processFiles(files) {
 
 if (isMainThread) {
   program
+    .name("squoosh-cli")
     .version(version)
     .arguments("<files...>")
     .option("-d, --output-dir <dir>", "Output directory", ".")