add description

README

@@ -1,6 +1,17 @@
 			FusionInventory Agent
 			---------------------
 
+Description
+-----------
+The fusioinventory agent is a generic agent, running on each managed node. It
+can perform a certain number of actions, called tasks, according to its own
+execution plan, or on behalf of a GLPI server with fusioninventory plugin,
+acting as a control point.
+
+Two of these tasks are included in agent source distribution, local inventory
+and wake on lan. Other tasks are distributed separatly, excepted for binary
+distributions where they are bundled together.
+
 Dependencies
 ------------