initial "more information" about updating (#596)

Still some work to be done.

docs/custom/documents/updating.md

@@ -1,11 +1,42 @@
-# About the Rewrite
-The rewrite takes a much more OOP approach than previous versions, which allows code to be much more manageable.
+# About Version 9.0
+The 9.0 rewrite takes a much more OOP approach than previous versions, which allows code to be much more manageable.
 It's been rebuilt from the ground up and should be much more stable, fixing caching issues that affected
 older versions and it also has support for new Discord Features, such as emojis.
 
 ## Upgrading your code
-The rewrite has a _lot_ of breaking changes. Major methods, e.g. `client.sendMessage(channel, message)` have been moved
-from the Client class towards their respective classes - `textChannel.sendMessage(message)`. You can find out the full
-extent of these changes by looking at the classes in the documentation.
+Version 9, while containing a number of breaking changes, does not require a lot of changes in the code logic. 
+It does, however, require changes in some of the method changes. This is because most of the methods have been
+moved away from the <Client> class into other classes where they belong.
 
-Additionally, some event names and parameters have changed - you should revisit these.
+Here are a few examples of methods that has changed: 
+
+* `Client.sendMessage(channel, message)` ==> `TextChannel.sendMessage(message)`
+  * `Client.sendMessage(user, message)` ==> `User.sendMessage(message)`
+* `Client.updateMessage(message, "New content") ==> `Message.edit("New Content")`
+* `Client.getChannelLogs(channel, limit)` ==> `TextChannel.fetchMessages({options})`
+* `Server.detailsOfUser(User)` ==> `Server.members.get(User).properties` (retrieving a member gives a GuildMember object)
+* `Client.joinVoiceChannel(voicechannel)` => `VoiceChannel.join()`
+
+A couple more important details: 
+
+* `Client.loginWithToken("token")` ==> `client.login("token")`
+* `Client.servers.length` ==> `client.guilds.size` (all instances of `server` are now `guild`)
+
+## Callbacks
+
+Version 9.0 eschews callbacks in favour of Promises. This means all code relying on callbacks must be changed.
+
+For example, the following code: 
+
+```js
+bot.getChannelLogs(channel, 100, function(messages) {
+  console.log(messages.length + " messages found);
+});
+```
+
+```js
+msg.channel.getMessages({limit: 100})
+.then(messages => {
+  console.log(messages.length + " messages found);
+});
+```