Update CONTRIBUTING.md

Add section about code style.

Author: drinckes

CONTRIBUTING.md

@@ -1,24 +1,43 @@
 Want to contribute? Great! First, read this page (including the small print at the end).
 
-### Before you contribute
+## Before you contribute
 Before we can use your code, you must sign the
 [Google Individual Contributor License Agreement](https://developers.google.com/open-source/cla/individual?csw=1)
-(CLA), which you can do online. The CLA is necessary mainly because you own the
+(CLA), which you can do online.
+
+The CLA is necessary mainly because you own the
 copyright to your changes, even after your contribution becomes part of our
 codebase, so we need your permission to use and distribute your code. We also
 need to be sure of various other things—for instance that you'll tell us if you
-know that your code infringes on other people's patents. You don't have to sign
+know that your code infringes on other people's patents.
+
+You don't have to sign
 the CLA until after you've submitted your code for review and a member has
 approved it, but you must do it before we can put your code into our codebase.
 Before you start working on a larger contribution, you should get in touch with
 us first through the issue tracker with your idea so that we can help out and
 possibly guide you. Coordinating up front makes it much easier to avoid
 frustration later on.
 
-### Code reviews
+## Code reviews
 All submissions, including submissions by project members, require review. We
 use Github pull requests for this purpose.
 
-### The small print
+## Code Style
+Programs written in Go must be formatted with `gofmt`. For other languages, we use the 
+[Google style guides](https://google.github.io/styleguide/) for code styling. Specifically, this means:
+
+* Line length: 80 chars (Java 100)
+* No extra whitespace around arguments `(code)` not `( code )`
+*  K & R style braces:
+```java
+if (condition()) {
+  something();
+} else {
+  somethingElse();
+}
+```
+
+## The small print
 Contributions made by corporations are covered by a different agreement than
 the one above, the Software Grant and Corporate Contributor License Agreement.