docs: add a section about the ROI in raster_class

doc/source/raster_class.md

@@ -262,6 +262,19 @@ rast_crop = rast.crop(crop_geom=(0.3, 0.3, 1, 1))
 print(rast_crop.bounds)
 ```
 
+A crop can also be done during its initialization by passing a Region of Interest (ROI) to the Raster class via the `roi` parameter.
+The `roi` can be specified in two formats:
+- **Pixel-based ROI:** Defined by the pixel coordinates with the following keys: `left`, `bottom`, `right`, and `top`.
+- **Georeferenced ROI:** Defined by geographical coordinates with the following keys: `x_min`, `x_max`, `y_min`, `y_max` and optional `crs` (Coordinate Reference System, defaults to EPSG:4326 if not provided).
+
+```{code-cell} ipython3
+# Initialize a raster with a pixel-based ROI
+rast_roi = gu.Raster(filename_rast, load_data=True, roi={'left': 100, 'bottom': 200, 'right': 400, 'top': 500})
+
+# Initialize a raster with a georeferenced ROI
+rast_roi = gu.Raster(filename_rast, load_data=True, roi={'lat_min': 630175, 'lat_max': 639175, 'lon_min': 4839545, 'lon_max': 4848545, 'crs': 'EPSG:32718'})
+```
+
 ## Polygonize
 
 Polygonizing a {class}`~geoutils.Raster` is done through the {func}`~geoutils.Raster.polygonize` function, which converts target pixels into a multi-polygon