Update Curvature and Slope support in README

update aspect, slope and curvature in feature matrix

Author: brendancol

README.md

@@ -209,9 +209,9 @@ In the GIS world, rasters are used for representing continuous phenomena (e.g. e
 | Name | NumPy xr.DataArray | Dask xr.DataArray | CuPy GPU xr.DataArray | Dask GPU xr.DataArray |
 |:----------:|:----------------------:|:--------------------:|:-------------------:|:------:|
 | [Aspect](xrspatial/aspect.py) | ✅️ | ✅️ | ✅️ | ✅️ |
-| [Curvature](xrspatial/curvature.py) | ✅️ |⚠️✅️ |⚠️✅️ | ⚠️✅️  |
+| [Curvature](xrspatial/curvature.py) | ✅️ |✅️ |✅️ | ✅️  |
 | [Hillshade](xrspatial/hillshade.py) | ✅️ | ✅️  | | |
-| [Slope](xrspatial/slope.py) | ✅️  | ✅️  | ✅️ | ⚠️✅️  |
+| [Slope](xrspatial/slope.py) | ✅️  | ✅️  | ✅️ | ✅️  |
 | [Terrain Generation](xrspatial/terrain.py) | ✅️ | ✅️ | ✅️ | |
 | [Viewshed](xrspatial/viewshed.py) | ✅️ |  | | |
 | [Perlin Noise](xrspatial/perlin.py) | ✅️ | ✅️ | ✅️ | |