typo in tabpanel, fixes #293
Merge branch 'inaccuracy/aria-typo' of github.com:mpiotrowicz/a11yproject.com into mpiotrowicz-inaccuracy/aria-typo

* 'inaccuracy/aria-typo' of github.com:mpiotrowicz/a11yproject.com:
  typo in tabpanel, fixes #293
Merge branch 'mpiotrowicz-inaccuracy/aria-typo' into gh-pages

* mpiotrowicz-inaccuracy/aria-typo:
  typo in tabpanel, fixes #293