Started dev setup documentation, re #1.

Author: mboersma

docs/contributing/devsetup.rst

@@ -1,9 +1,87 @@
 :title: Developer Setup
-:description: -- todo: change me
-:keywords: deis, documentation, contributing, developer, setup
+:description: Setting up your workstation for Deis development
+:keywords: deis, documentation, contributing, developer, setup, chef, knife
 
 .. _devsetup:
 
 Developer Setup
 ===============
 
+Thank you for contributing to Deis! We have tried to make it simple
+to work on Deis, but as an open PaaS there are necessarily several
+moving pieces and some setup required. We welcome any suggestions for
+automating or simplifying this process.
+
+
+Prerequisites
+-------------
+
+We assume you have a modern UNIX-like environment, such as Linux or
+Mac OS X. Many of the tools listed below will probably be present
+already, but install those that are not:
+
+- git
+- GNU Make
+- `Python`_ 2.7.x
+- `Ruby`_ 1.9 (for knife.rb)
+- `Amazon EC2 API Tools`_
+
+To contribute code back to Deis, you must also have a GitHub.com account
+in order to create a pull request.
+
+
+Fetch Git Repositories
+----------------------
+
+.. code-block:: console
+
+	$ git clone -q https://github.com/opdemand/deis.git
+	$ git clone -q https://github.com/opdemand/deis-cookbook.git
+	$ cd deis
+
+
+Make a Virtualenv
+-----------------
+
+To keep Deis` requirements separate from other development you may do,
+it's preferable to create a **virtual environment** for python.
+
+.. code-block:: console
+
+	$ virtualenv venv --prompt='(deis)'
+	New python executable in venv/bin/python
+	Installing Setuptools.................................done.
+	Installing Pip........................................done.
+	$ source venv/bin/activate
+	(deis)$ pip install -r dev_requirements.txt --use-mirrors
+	Downloading/unpacking azure>=0.7.0 (from -r dev_requirements.txt (line 2))
+	  Downloading azure-0.7.0.zip (76kB): 76kB downloaded
+	  Running setup.py egg_info for package azure
+	Downloading/unpacking boto>=2.9.8 (from -r dev_requirements.txt (line 3))
+	...
+	Successfully installed azure boto ...
+	Cleaning up...
+	(deis)$
+
+Make sure you install the requirements in the dev_requirements.txt file,
+which contains several additions over the runtime requirements.txt file.
+Please see the `virtualenv documentation`_ for more details on python virtual
+environments.
+
+
+Install knife.rb
+----------------
+
+** Coming soon... ***
+
+
+Set Up a Chef Account
+---------------------
+
+** Coming soon... ***
+
+
+.. _`virtualenv documentation`: http://www.virtualenv.org/en/latest/
+.. _`Python`: http://python.org/
+.. _`Ruby`: http://ruby-lang.org/
+.. _`Amazon EC2 API Tools`: http://aws.amazon.com/developertools/Amazon-EC2/351