doc: add more gophers

R=golang-dev, bradfitz, r
CC=golang-dev
https://golang.org/cl/5753047
diff --git a/doc/help.html b/doc/help.html
index 2efda4e..fadf80a 100644
--- a/doc/help.html
+++ b/doc/help.html
@@ -3,6 +3,8 @@
 	"Path": "/help/"
 }-->
 
+<img class="gopher" src="/doc/gopher/help.png"/>
+
 <p>
 Need help with Go? Try these resources.
 </p>