Add use category to declare what is the use of document.

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@31138 20353a03-c40f-0410-a6d1-a30d3c3de9de

product/ERP5/PropertySheet/Amount.py

@@ -103,7 +103,7 @@ class Amount:
  )
 
   _categories = ('resource', 'quantity_unit',
-                 'base_application', 'base_contribution',
+                 'base_application', 'base_contribution', 'use',
                  # Acquired categories
                  'product_line', )