update TODOs

README.md

@@ -366,14 +366,25 @@ Then, when we call `getInventory(node=N1, resource=R1)`, the following lines are
 And the value returned by `getInventory` is 4, which matches what has been counted on the floor during inventory procedure.
 
 
+XXX what about price for Inventory ? Is inventory a movement or a path ?
+
+
 # Flow API
-linear movements
+TODO: interpolation API
+
+
+# Value of stocks
+TODO: explain purchase price, evaluation methods (FIFO, weighted average, etc)
 
-# Example uses
+
+# Example use cases
 
 ## Warehouse Inventory
 
 ## Time 
 
+
+
 # Tracking API
+
 XXX or another doc ?