introducing distinct as per previous ts meeting

Weiwu Zhang · Weiwu Zhang · commit 5e5c5a27f90f · 2020-08-07T19:34:22.000+10:00
diff --git a/schema/tokenscript.xsd b/schema/tokenscript.xsd
@@ -267,6 +267,7 @@
                 <element ref="ts:origins"/>
             </sequence>
             <attribute name="name" use="required" type="NCName"/>
+            <attribute name="distinct" type="boolean" default="false"/>
             <attribute name="oid" type="NMTOKEN"/>
         </complexType>
     </element>
