Add extracted source directory and README navigation

extracted-source/node_modules/@commander-js/extra-typings/esm.mjs

@@ -0,0 +1,16 @@
+import extraTypingsCommander from './index.js';
+
+// wrapper to provide named exports for ESM.
+export const {
+  program,
+  createCommand,
+  createArgument,
+  createOption,
+  CommanderError,
+  InvalidArgumentError,
+  InvalidOptionArgumentError, // deprecated old name
+  Command,
+  Argument,
+  Option,
+  Help,
+} = extraTypingsCommander;