Fixed README regarding threshold -1 feature [no ci]

README.md

@@ -57,11 +57,13 @@ lungtumormask input_file output_file
 lungtumormask patient_01.nii.gz mask_01.nii.gz
 
 # Custom arguments
-lungtumormask patient_01.nii.gz mask_01.nii.gz --lung-filter --threshold 0.3 --radius 3 --batch-size 8 --cpu --threshold -1
+lungtumormask patient_01.nii.gz mask_01.nii.gz --lung-filter --threshold 0.3 --radius 3 --batch-size 8 --cpu
 ```
 
 In the last example, we filter tumor candidates outside the lungs, use a lower probability threshold to boost recall, use a morphological smoothing step
-to fill holes inside segmentations using a disk kernel of radius 3, `--cpu` to disable the GPU during computation, and set `--threshold` to -1 to output the raw probability map.
+to fill holes inside segmentations using a disk kernel of radius 3, and `--cpu` to disable the GPU during computation.
+
+You can also output the raw probability map (without any post-processing), by setting `--threshold -1` instead. By default a threshold of 0.5 is used.
 
 ## [Applications](https://github.com/VemundFredriksen/LungTumorMask#applications)
 * The software has been successfully integrated into the open platform [Fraxinus](https://github.com/SINTEFMedtek/Fraxinus).