documented parameterised events

README.md

@@ -81,7 +81,7 @@ class Job
     state :running
 
     event :run, :after => :notify_somebody do
-      transitions :from => :sleeping, :to => :running
+      transitions :from => :sleeping, :to => :running, :on_transition => Proc.new {|obj, *args| obj.set_process(*args) }
     end
 
     event :sleep do
@@ -89,6 +89,10 @@ class Job
     end
   end
 
+  def set_process(name)
+    ...
+  end
+
   def do_something
     ...
   end
@@ -116,6 +120,15 @@ Here you can see a list of all possible callbacks, together with their order of
   event:after
 ```
 
+Also, you can pass parameters to events:
+
+```ruby
+  job = Job.new
+  job.run(:running, :defragmentation)
+```
+
+In this case the set_process would be called with `:defagmentation` argument.
+
 ### Guards
 
 Let's assume you want to allow particular transitions only if a defined condition is