1.) Create server. Add yarn modules: mongoose and express
2.) Connect to MongoDB (use db 'AuthDemo')
3.) Create a User Schema and Model, this Schema will take a username(unique) and a password.
4.) Create a route, '/register' that takes a post method. The body will have a username and password field.
5.) Using Postman create one new user (with plain text password)
6.) Add the yarn module bcrypt
7.) On the UserSchema, add a .pre('save' middleware.
8.) The mongoose pre middleware will take the existing password and hash it.
9.) Store the new hashed password on the User document.