2.6.2 Orientation - Understanding doc updated and ready for review

Hi Folks,

I've updated the 2.6.2 Orientation Understanding doc based on feedback and
an earlier survey.  Please take a look and let me know if you have any
further changes or suggestions.

Updated Understanding Orientation
<https://rawgit.com/w3c/wcag21/orientation/understanding/21/orientation.html>
doc

For reference:
SC 2.6.2 Orientation <https://www.w3.org/TR/WCAG21/#orientation>  (Note:
use the link above to access the branch with the updated Understanding doc
- not the link that is on the success criteria in the 2.1 CR).


Thanks,
Marc