Classify module: ignore nans (#534)

* quantile: ignore nans

* natural breaks: ignore nans

* ignore inf

* update examples

* updated functionality matrix

* README: added true_color

Author: thuydotm

README.md

@@ -81,10 +81,10 @@ 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 |
 |:----------:|:----------------------:|:--------------------:|:-------------------:|:------:|
-| [Equal Interval](xrspatial/classify.py) |✅️ |✅ | ✅ |✅️ |
-| [Natural Breaks](xrspatial/classify.py) |✅️ |✅ | ✅ |✅️ |
+| [Equal Interval](xrspatial/classify.py) |✅️ |✅ | ✅ | ️ |
+| [Natural Breaks](xrspatial/classify.py) |✅️ |  | ✅ | ️ |
 | [Reclassify](xrspatial/classify.py) |✅️ |✅ | ✅ |✅ |
-| [Quantile](xrspatial/classify.py) |✅️ | ✅ |✅ |✅️|
+| [Quantile](xrspatial/classify.py) |✅️ | ✅ |✅ |  ️|
 
 -------
 
@@ -113,6 +113,7 @@ In the GIS world, rasters are used for representing continuous phenomena (e.g. e
 | [Normalized Difference Vegetation Index (NDVI)](xrspatial/multispectral.py) | ✅️ |✅️ | ✅️ |✅️ |
 | [Soil Adjusted Vegetation Index (SAVI)](xrspatial/multispectral.py) | ✅️ |✅️ | ✅️ |✅️ |
 | [Structure Insensitive Pigment Index (SIPI)](xrspatial/multispectral.py) | ✅️ |✅️ | ✅️ |✅️ |
+| [True Color](xrspatial/multispectral.py) | ✅️ | ️ | ✅️ | ️ |
 
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