README: fix typo.
README: fix typo.

From #1.

pearofducks/strap,mikemcquaid/strap,joewilliams/strap,tarebyte/strap,pearofducks/strap,joewilliams/strap,pearofducks/strap,TheLady/strap,mikemcquaid/strap,joewilliams/strap,TheLady/strap,tarebyte/strap,TheLady/strap,mikemcquaid/strap,tarebyte/strap