Add Jeffrey Yasskin as alternate SG rep for Google

Author: cwilso

README.md

@@ -56,7 +56,7 @@ Workstream Participant Agreement which is maintained as
 ## Steering Group representatives
 
 * Anne van Kesteren (Apple) [@annevk](https://github.com/annevk) (Alternate: Theresa O’Connor [@hober](https://github.com/hober))
-* Chris Wilson (Google) [@cwilso](https://github.com/cwilso)
+* Chris Wilson (Google) [@cwilso](https://github.com/cwilso) (Alternate: Jeffrey Yasskin [@jyasskin](https://github.com/jyasskin))
 * Diego González (Microsoft) [@diekus](https://github.com/diekus)
 * Tantek Çelik (Mozilla) [@tantek](https://github.com/tantek) (Alternate: Simon Pieters [@zcorpan](https://github.com/zcorpan))