Updated code snippets to match generated source

_browser/hello-blockstack.md

@@ -212,23 +212,26 @@ All of the code in the file is wrapped in an event
 listener.
 
 ```js
-document.addEventListener("DOMContentLoaded", function(event) {
+document.addEventListener("DOMContentLoaded", event => {
 })
 ```
 
 This listener that waits until the DOM content is loaded. Then, it creates an auth request and redirects the user to sign in:
 
 ```js
-document.getElementById('signin-button').addEventListener('click', function() {
+document.getElementById('signin-button').addEventListener('click', event => {
-  blockstack.redirectUserToSignIn()
+  event.preventDefault()
+  userSession.redirectToSignIn()
 })
 ```
 
-You can find the `redirectUserToSignIn()` function is part of the [Blockstack Javascript documentation](https://blockstack.github.io/blockstack.js/). There is also a sign out button handler. This handler deletes the local user data and signs the user out:
+You can find the `redirectToSignIn()` function is part of the [Blockstack Javascript documentation](https://blockstack.github.io/blockstack.js/). There is also a sign out button handler. This handler deletes the local user data and signs the user out:
 
 ```js
-document.getElementById('signout-button').addEventListener('click', function() {
+document.getElementById('signout-button').addEventListener('click', event => {
-  blockstack.signUserOut(window.location.origin)
+  event.preventDefault()
+  userSession.signUserOut()
+  window.location = window.location.origin
 })
 ```
 
@@ -236,7 +239,7 @@ The handlers are followed by a `showProfile()` function for showing the user's p
 
 ```js
 function showProfile(profile) {
-  var person = new blockstack.Person(profile)
+  let person = new blockstack.Person(profile)
   document.getElementById('heading-name').innerHTML = person.name() ? person.name() : "Nameless Person"
   if(person.avatarUrl()) {
     document.getElementById('avatar-image').setAttribute('src', person.avatarUrl())
@@ -259,12 +262,14 @@ several states the user can be in:
 The application handles these situations as followed:
 
 ```js
-var userSession = new UserSession()
+const appConfig = new blockstack.AppConfig()
+const userSession = new blockstack.UserSession({ appConfig: appConfig })
+
 if (userSession.isUserSignedIn()) {
-  var profile = userSession.loadUserData().profile
+  const { profile } = userSession.loadUserData()
   showProfile(profile)
 } else if (userSession.isSignInPending()) {
-  userSession.handlePendingSignIn().then(function(userData) {
+  userSession.handlePendingSignIn().then(userData => {
     window.location = window.location.origin
   })
 }