Sponsor-Promotion-Plan.md

 List of tasks for summit and sprint sponsor promotion:
 
 * [X] July 1 - Initial sponsor thanks to community
-* [ ] July 15 - Sponsor recognition in community newsletter
+* [X] July 15 - Sponsor recognition in community newsletter
 * [ ] August 1 - Sponsor recognition in community newsletter
 * [ ] August 15 - Sponsor recognition in community newsletter
 * [ ] September 1 - Sponsor recognition in community newsletter