Tweaks to Dockerfile tutorial

Made a few tweaks to Dockerfile tutorial links and removed some cruft from the tutorial itself.

Docker-DCO-1.1-Signed-off-by: Fred Lifton <fred.lifton@docker.com> (github: fredlf)

docs/sources/reference/builder.md

@@ -14,7 +14,8 @@ successively.
 This page discusses the specifics of all the instructions you can use in your
 `Dockerfile`. To further help you write a clear, readable, maintainable
 `Dockerfile`, we've also written a [`Dockerfile` Best Practices
-guide](/articles/dockerfile_best-practices).
+guide](/articles/dockerfile_best-practices). Lastly, you can test your
+Dockerfile knowledge with the [Dockerfile tutorial](/userguide/level1).
 
 ## Usage
 

docs/sources/userguide/dockerimages.md

@@ -168,7 +168,6 @@ update and create images.
 1. We can update a container created from an image and commit the results to an image.
 2. We can use a `Dockerfile` to specify instructions to create an image.
 
-To learn more, check out the [Dockerfile tutorial](/userguide/level1).
 
 ### Updating and committing an image
 
@@ -539,6 +538,9 @@ Until now we've seen how to build individual applications inside Docker
 containers. Now learn how to build whole application stacks with Docker
 by linking together multiple Docker containers.
 
+Test your Dockerfile knowledge with the
+[Dockerfile tutorial](/userguide/level1).
+
 Go to [Linking Containers Together](/userguide/dockerlinks).
 
 

docs/sources/userguide/level2.md

@@ -89,9 +89,6 @@ RUN apt-get install -y <input id="gcc" class="l_fill" type="text"><br>
     
 ## What's next?
 <p>
-Thanks for going through our tutorial! We will be posting Level 3 shortly. Follow us on twitter<br>
-<a href="https://twitter.com/docker" class="twitter-follow-button" data-show-count="false">Follow @docker</a>
-<script>!function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0],p=/^http:/.test(d.location)?'http':'https';if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src=p+'://platform.twitter.com/widgets.js';fjs.parentNode.insertBefore(js,fjs);}}(document, 'script', 'twitter-wjs');</script>
-</p>
-<p>In the meantime, check out this <a href="http://crosbymichael.com/dockerfile-best-practices.html">blog post</a> by Michael Crosby that describes Dockerfile Best Practices.</p>
+Thanks for going through our tutorial! We will be posting Level 3 in the future. 
+
 <a title="creating our own images" class="btn btn-primary" href="/userguide/dockerimages/#creating-our-own-images">Back to the Docs!</a>