go.talks: add video links to GopherCon slides

LGTM=kamil.kisiel
R=golang-codereviews, kamil.kisiel
CC=golang-codereviews
https://golang.org/cl/92620044
diff --git a/2014/c2go.slide b/2014/c2go.slide
index 53f067a..9f38b9a 100644
--- a/2014/c2go.slide
+++ b/2014/c2go.slide
@@ -8,6 +8,14 @@
 
 http://golang.org/
 
+
+* Video
+
+A video of this talk was recorded at GopherCon in Denver.
+
+.link https://www.youtube.com/watch?v=QIE5nV5fDwA Watch the talk on YouTube
+
+
 * Go Compiler
 
 * Go Compiler
diff --git a/2014/go4gophers.slide b/2014/go4gophers.slide
index ce47430..f840d83 100644
--- a/2014/go4gophers.slide
+++ b/2014/go4gophers.slide
@@ -8,6 +8,13 @@
 adg@golang.org
 
 
+* Video
+
+A video of this talk was recorded at GopherCon in Denver.
+
+.link https://www.youtube.com/watch?v=dKGmK_Z1Zl0 Watch the talk on YouTube
+
+
 * About me
 
 .image go4gophers/gopherswim.jpg
diff --git a/2014/hellogophers.slide b/2014/hellogophers.slide
index 0930ba5..4a6daf1 100644
--- a/2014/hellogophers.slide
+++ b/2014/hellogophers.slide
@@ -8,6 +8,13 @@
 http://golang.org/s/plusrob
 http://golang.org
 
+* Video
+
+A video of this talk was recorded at GopherCon in Denver.
+
+.link https://www.youtube.com/watch?v=VoS7DsT1rdM Watch the talk on YouTube
+
+
 * Hello, gophers!
 
 .image hellogophers/gophers.jpg 500 750