Update legion docs with join hook info

Legion.rst

@@ -9,7 +9,13 @@ Each node has a valor (different from the others, if possible).
 
 The node with the higher valor is the Lord of the Legion (or if you like a more engineer-friendly term: the master)
 
-This constant fight generates 4 kind of events: start of the fight (setup), end of the fight (death), becoming a lord (lord), loosing the lord title (unlord).
+This constant fight generates 5 kind of events:
+
+1. setup - when legion subsystem is started on a node
+2. join - the first time quorum is reached, only on the newly joined node
+3. lord - when node becomes a lord
+4. unlord - when node loses the lord title
+5. death - when legion subsystem is shuting down
 
 You can trigger actions every time such an event rises, and this should switch-on the light on your brain...