UPGRADE_GUIDE.md in volt-0.9.4.pre1

- old
+ new

@@ -1,7 +1,11 @@
 # 0.9.2 to 0.9.3
 
+Upgrading from 0.9.2 should be fairly simple, just implement the following:
+
+## Gemfile
+
 Add the following to your gemfile:
 
 ```ruby
 # Use rbnacl for message bus encrpytion
 # (optional, if you don't need encryption, disable in app.rb and remove)
@@ -11,6 +15,14 @@
 # Asset compilation gems, they will be required when needed.
 gem 'csso-rails', '~> 0.3.4', require: false
 gem 'uglifier', '>= 2.4.0', require: false
 
 gem 'volt-mongo'
-```
+```
+
+## Store Promises
+
+The api for accessing the store collection has changed, to better understand the changes, watch [this explainer video](https://www.youtube.com/watch?v=1RX9i8ivtWI).
+
+## id vs _id
+
+Everywhere you were using ```_id```, you should now just use ```id```.  Volt's mongo adaptor will map ```id``` to ```_id``` when saving or querying.  This change will make moving between databases easier.
\ No newline at end of file