Update prediction.rst

[NickHilton]

Typo for pred_contribs and pred_interactions

See method here for confirmation of param names

def predict(
        self,
        data: DMatrix,
        output_margin: bool = False,
        pred_leaf: bool = False,
        pred_contribs: bool = False,
        approx_contribs: bool = False,
        pred_interactions: bool = False,
        validate_features: bool = True,
        training: bool = False,
        iteration_range: Tuple[int, int] = (0, 0),
        strict_shape: bool = False,
    ) -> np.ndarray:

[trivialfis]

Nice fix!