docs: add UPGRADING.md

Author: kenjis

UPGRADING.md

@@ -2,7 +2,9 @@
 
 ## Version 1.0.0-beta.6 to 1.0.0-beta.7
 
-### Install New Config AuthToken.php
+### Mandatory Config Changes
+
+#### New Config\AuthToken
 
 A new Config file **AuthToken.php** has been introduced. Run `php spark shield:setup`
 again to install it into **app/Config/**, or install it manually.
@@ -11,6 +13,16 @@ Then change the default settings as necessary. When using Token authentication,
 the default value has been changed from all accesses to be recorded in the
 ``token_logins`` table to only accesses that fail authentication to be recorded.
 
+#### Config\Auth
+
+The following items have been moved. They are no longer used and should be removed.
+
+- `$authenticatorHeader` and `$unusedTokenLifetime` are moved to `Config\AuthToken`.
+
+The following items have been added. Copy the properties in **src/Config/Auth.php**.
+
+- `$usernameValidationRules` and `$emailValidationRules` are added.
+
 ## Version 1.0.0-beta.3 to 1.0.0-beta.4
 
 ### Important Password Changes