Add min/max attributes to COMMAND tag

klish.xsd

@@ -432,6 +432,8 @@
 		<xs:attribute name="name" type="xs:string" use="optional"/>
 		<xs:attribute name="help" type="xs:string" use="optional"/>
 		<xs:attribute name="mode" type="entry_mode_t" use="optional" default="sequence"/>
+		<xs:attribute name="min" type="xs:string" use="optional" default="1"/>
+		<xs:attribute name="max" type="xs:string" use="optional" default="1"/>
 		<xs:attribute name="ref" type="xs:string" use="optional"/>
 		<xs:attribute name="value" type="xs:string" use="optional"/>
 		<xs:attribute name="restore" type="xs:boolean" use="optional" default="false"/>