DOC - fixed typo
DOC - fixed typo

nilgoyyou/dipy,FrancoisRheaultUS/dipy,villalonreina/dipy,matthieudumont/dipy,FrancoisRheaultUS/dipy,StongeEtienne/dipy,nilgoyyou/dipy,villalonreina/dipy,StongeEtienne/dipy,matthieudumont/dipy