_content/blog: fix link to sample in h2push post

The link pointed to the old home of the blog.
Moreover, in the new world of modules, `go get` isn't a very convenient
way to obtain samples, so pointing directly to the code repository
instead.

Change-Id: I2dca199cf817920347445a5db17521a349a93c64
Reviewed-on: https://go-review.googlesource.com/c/website/+/522677
Run-TryBot: Eli Bendersky <eliben@google.com>
Reviewed-by: Eli Bendersky <eliben@google.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
Auto-Submit: Eli Bendersky <eliben@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>

_content/blog/h2push.md

@@ -62,9 +62,7 @@ then the `PUSH_PROMISE` should include an Accept-Encoding value:
 
 {{code "h2push/pusher.go" `/START1/` `/END1/`}}
 
-A fully working example is available at:
-
-	$ go get golang.org/x/blog/content/h2push/server
+A fully working example is [available here](https://cs.opensource.google/go/x/website/+/master:_content/blog/h2push/server/).
 
 If you run the server and load [https://localhost:8080](https://localhost:8080),
 your browser's developer tools should show that `app.js` and