new users should be warned about cson

improper trailing and leading spaces can cause your bindings to fail.Since cson has very little adoption relative to json, I think it's important to warn new users that they need to understand CoffeeScript notation or else a single space could break their file. I spent one full hour today trying to get an auto-indent mapping to work. The solution involved adding one leading space!
Update keymap.cson
Update keymap.cson
Add initial panel API. 

It can only add things to the left right now.
Add panel containers
Panel containers have the orientation
Integrate the pane containers into the workspace
Render proper atom-panels as children of containers
Panel container probably not public
orientation -> location
Rename custom element so as not to clash
Remove location junk from panel creation
Add matcher toHide()
Add hide/show ability for panels
Set the heights of atom panels for location left and right.
Add priority system to the panels
Fix spec
Doc Panel class
:memo: Doc the new panel methods
Deprecate workspace pane methods