Update read_geotif.md

docs/read_geotif.md

@@ -2,13 +2,14 @@
 
 Read in data (from tif format, most likely georeferenced image data). 
 
-**plantcv.geospatial.read_geotif**(*filename, mode="rgb"*)
+**plantcv.geospatial.read_geotif**(*filename, bands="rgb"*)
 
 **returns** [PlantCV Spectral_data](https://plantcv.readthedocs.io/en/latest/Spectral_data/) object instance 
 
 - **Parameters:**
     - filename - Filepath to .tif data 
-    - mode - Mode for geotif reading  
+    - bands - Comma separated string representing the order of image bands (default bands="R,G,B"), or a list of wavelengths (e.g. bands=[650,560,480])
+        - Supported keys for bands and their default_wavelengths = {"R": 650, "G": 560, "B": 480, "RE": 717, "N": 842, "NIR": 842}
 
 - **Example use:**
     - below
@@ -19,7 +20,7 @@ import plantcv.plantcv as pcv
 import plantcv.geospatial as geo
 
 # Read geotif in
-marker = geo.read_geotif(filename="./data/example_img.tif", mode="rgb")
+marker = geo.read_geotif(filename="./data/example_img.tif", bands="r,g,b,NIR,RE")
 
 ```