Rename default chest to "Wooden Chest"

All the chests added by technic specify their material in their
description, so the description "Chest" for the default chest looks
ambiguous.  Rename it to seamlessly fit into the range of chest types.

technic_chests/locale/template.txt

@@ -30,6 +30,7 @@ Gold =
 Iron =
 Mithril =
 Silver =
+Wooden =
 
 # Sorting
 Sort =