Add a link to the Sass community guidelines.

Closes #1748

CODE_OF_CONDUCT.md

@@ -0,0 +1,10 @@
+Sass is more than a technology; Sass is driven by the community of individuals
+that power its development and use every day. As a community, we want to embrace
+the very differences that have made our collaboration so powerful, and work
+together to provide the best environment for learning, growing, and sharing of
+ideas. It is imperative that we keep Sass a fun, welcoming, challenging, and
+fair place to play.
+
+[The full community guidelines can be found on the Sass website.][link]
+
+[link]: http://sass-lang.com/community-guidelines