Move Cordova content from wiki to website
Update based on QA feedback

* Add link to Crosswalk/Chrome version mapping table for debugging.
* Remove '/' in commands, which cause them not to work on Windows.
* Make it clear that plugins can be added to any Crosswalk Cordova
application using these instructions.
Merge pull request #115 from crosswalk-project/cordova-1630

Crosswalk Cordova tutorial