Add a reference to the Trello board to CONTRIBUTING.md

CONTRIBUTING.md

@@ -1,20 +1,21 @@
 # How to contribute
 
+* Visit the [PuppetDB board on Trello](http://links.puppetlabs.com/puppetdb-trello)
 * Make sure you have a [Redmine account](http://projects.puppetlabs.com)
 * Make sure you have a [GitHub account](https://github.com/signup/free)
-* Submit a ticket for your issue, assuming one does not already exist. 
+* Submit a ticket for your issue, assuming one does not already exist.
   * Clearly describe the issue including steps to reproduce when it is a bug.
   * Make sure you fill in the earliest version that you know has the issue.
 * Fork the repository on GitHub
 
 ## Making Changes
 
 * Create a branch off of the branch you want to base off of.
-  * This is usually the master branch. 
+  * This is usually the master branch.
   * Only target release branches if you are certain your fix must be on that branch.
 * Make commits of logical units.
 * Check for unnecessary whitespace with "git diff --check" before committing.
-* Make sure your commit messages are in the proper format. 
+* Make sure your commit messages are in the proper format.
 
 ````
     (#Ticket Number) What you are changing with this commit
@@ -32,7 +33,7 @@
 * Push your changes to a topic branch in your fork of the repository.
 * Submit a pull request to the repository in the puppetlabs organization.
 * Update your Redmine ticket to mark that you have submitted code.
-   
+
 # Additional Resources
 
 * [More information on contributing](http://projects.puppetlabs.com/projects/puppet/wiki/Development_Lifecycle)