Updated carousel 1 example ready for additional review and comments

Updated carousel example 1:
https://raw.githack.com/w3c/aria-practices/issue458-add-carousel-example/examples/carousel/carousel-1/carousel-1.html


Changes:

  1.  Pause button changed from a toggle button to a button that changes its label to indicate the function I will perform (e.g. Pause or Resume rotation)
  2.  Added live region to slide container.  The live region is set to polite when the auto-rotation is disabled, when auto-rotation is enabled it is set to off.
  3.  Added the role group to each slide container, and included aria-roledescription=”slide”, aria-label and aria-describedby.

Please put comments in issue 458:
https://github.com/w3c/aria-practices/issues/458