`.table` style is duplicate in `List groups in panels` and `Tables in panels`

fix typo

Add background-color to carousel.

Navigation arrows were aligned to the top of page. Vertically centered them in this fix.

Set a background color for the carousel example so that white text is now legible. Also fixed typo on line 97.

Remove unnecessary trailing comma in Gruntfile.js

    validation: {
      options: {
        reset: true
      },