Updated README to express the support of custom collate functions.

Author: msallin

README.md

@@ -24,7 +24,7 @@ The following features are supported:
 - Auto increment (An int PrimaryKey will automatically be incremented and you can explicit set the "AUTOINCREMENT" constraint to a PrimaryKey using the Autoincrement-Attribute)
 - Index (Decorate columns with the `Index` attribute. Indices are automatically created for foreign keys by default. To prevent this you can remove the convention `ForeignKeyIndexConvention`)
 - Unique constraint (Decorate columns with the `UniqueAttribute`, which is part of this library)
-- Collate constraint (Decorate columns with the `CollateAttribute`, which is part of this library)
+- Collate constraint (Decorate columns with the `CollateAttribute`, which is part of this library. Use `CollationFunction.Custom` to specify a own collation function.)
 - SQL default value (Decorate columns with the `SqlDefaultValueAttribute`, which is part of this library)
 
 ## Install