Add link to 1.0.3

Author: Brian Lonsdorf

RELEASENOTES.md

@@ -373,5 +373,6 @@ The following features are being marked as deprecated in this release and will b
 
 Lots of bug fixes and TLC.
 
+[1.0.3]: https://github.com/salesforce-ux/design-system/compare/v1.0.2...v1.0.3
 [1.0.2]: https://github.com/salesforce-ux/design-system/compare/v1.0.1...v1.0.2
 [1.0.1]: https://github.com/salesforce-ux/design-system/compare/v1.0.0...v1.0.1