Chapter 9: add hasing-with-bcrypt samples

Chapter09/hashing-with-bcrypt/hash.js

@@ -0,0 +1,7 @@
+const password = process.argv[2];
+const bcrypt = require("bcrypt");
+const saltRounds = 10;
+
+bcrypt.hash(password, saltRounds, (err, hash) => {
+  console.log(hash);
+});