playground: link to the playground source code in the help page
Fixes golang/go#23658
Change-Id: I68b68497af0a39c1026bfb320d774183ae627801
Reviewed-on: https://go-review.googlesource.com/98315
Reviewed-by: Andrew Bonventre <andybons@golang.org>
diff --git a/edit.html b/edit.html
index 0be1443..826e4fb 100644
--- a/edit.html
+++ b/edit.html
@@ -164,8 +164,10 @@
</ul>
<p>
-The article "<a href="https://blog.golang.org/playground" target="_blank">Inside
+The article "<a href="https://blog.golang.org/playground" target="_blank" rel="noopener">Inside
the Go Playground</a>" describes how the playground is implemented.
+The source code is available at <a href="https://go.googlesource.com/playground" target="_blank" rel="noopener">
+https://go.googlesource.com/playground</a>.
</p>
<p>