[x/blog] content: add link to Go Module Proxy talk

Change-Id: I03257e7d8e1a243e63374af79d06585f229a6638
Reviewed-on: https://go-review.googlesource.com/c/blog/+/310518
Trust: Katie Hockman <[email protected]>
Run-TryBot: Katie Hockman <[email protected]>
TryBot-Result: Go Bot <[email protected]>
Reviewed-by: Ian Lance Taylor <[email protected]>
X-Blog-Commit: 284484f1bcf685e509fbab127e155e24f9138ac4

Author: katiehockman

blog/content/experiment.article

@@ -1195,8 +1195,7 @@ And for individual developers and open source teams,
 the Go team at Google has [launched a proxy](https://groups.google.com/forum/#!topic/golang-announce/0wo8cOhGuAI) that serves
 as a public mirror of all open-source Go packages,
 and Go 1.13 will use that proxy by default when in module mode.
-Katie Hockman gave a talk about this system at Gophercon 2019.
-(We’ll add a link here when the video becomes available.)
+Katie Hockman gave a [talk about this system at Gophercon 2019](https://youtu.be/KqTySYYhPUE).
 
 **Go Modules Status**