Fixed README grammar error

README.md

@@ -83,7 +83,7 @@ made by LIQE.
    `JPEG compression` to `jpeg compression`, `JPEG2000 compression` to `jpeg2000
    compression`, `over-exposure` to `overexposure`, `under-exposure` to
    `underexposure`, `spatially-localized` to `spatial`, and `others` to `other`.
-   The scene types `indoor scene` has also been renamed to `indoor`, `night
+   The scene type `indoor scene` has also been renamed to `indoor`, `night
    scene` to `night`, and `still-life` to `still_life`. The distortion types
    have been pre-mapped back to the 11 types, and the naming for the scene and
    distortion types follows the source code of LIQE instead of the paper.