Improve module documentation and doc cleanup.

This adds lots of config module documentation in a standard format.
It will greatly improve the content at readthedocs.
Additionally:
 * Add a 'doc' env to tox.ini
 * Changed default highlight language for sphinx conf from python to yaml
   most examples in documentation are yaml configs
 * Updated datasource examples to highlight sh code properly

1 files changed, 15 insertions, 0 deletions

diff --git a/cloudinit/config/cc_emit_upstart.py b/cloudinit/config/cc_emit_upstart.py
index 98828b9e..a7be6351 100644
--- a/cloudinit/config/cc_emit_upstart.py
+++ b/cloudinit/config/cc_emit_upstart.py
@@ -18,6 +18,21 @@
 #    You should have received a copy of the GNU General Public License
 #    along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
+"""
+Emit Upstart
+------------
+**Summary:** emit upstart configuration
+
+Emit upstart configuration for cloud-init modules on upstart based systems. No
+user configuration should be required.
+
+**Internal name:** ``cc_emit_upstart``
+
+**Module frequency:** per always
+
+**Supported distros:** ubuntu, debian
+"""
+
 import os
 
 from cloudinit import log as logging