Add downloads page

Author: Abderrazek Boufahja

xml/FHIR-radiation-dose-summary.xml

@@ -57,6 +57,7 @@
 	<page key="many" name="(many)"/>
 	<page key="Home" name="Home"/>
 	<page key="Background" name="Background"/>
+	<page key="downloads" name="Downloads"/>
 	<page key="Architecture" name="Architecture and Implementation"/>
 	<page key="Testing" name="Testing and Conformance"/>
 	<page key="artifacts" name="Artifacts Summary"/>