add links and descriptions for SISO and DIS/RPR-FOM product study group

specifications/README.md

@@ -4,8 +4,8 @@
 real-time platform-level wargaming across multiple host computers and is used worldwide,
 especially by military organizations but also by other agencies such as those involved in
 space exploration and medicine.*
-* Wikipedia: [Distributed Interactive Simulation](https://en.wikipedia.org/wiki/Distributed_Interactive_Simulation)
-* [Simulation Interoperabilty Standards Organization (SISO)](https://www.sisostds.org)
+* Wikipedia: [Distributed Interactive Simulation (DIS)](https://en.wikipedia.org/wiki/Distributed_Interactive_Simulation) IEEE Standard
+* [Simulation Interoperabilty Standards Organization (SISO)](https://www.sisostds.org): "Simulation Interoperability and Reuse through Standards"
 * SISO Product Support Group (PSG): [DIS / RPR FOM PSG - Distributed Interactive Simulation / Real-time Platform Reference Federation Object Model](https://www.sisostds.org/StandardsActivities/SupportGroups/DISRPRFOMPSG.aspx)
 
 Manual download links follow.  IEEE standards must be downloaded manually while within NPS campus or firewall.