Update README.md

README.md

@@ -21,7 +21,7 @@ livermask --input path-to-input --output path-to-output
 ```
 
 | command | description |
-| ------------- | ------------- |
+| ----------------- | ------------- |
 | `--input` | the full path to the input data. Could be nifti file or directory (if directory is provided as input) |
 | `--output` | the full path to the output data. Could be either output name or directory (if directory is provided as input)  |
 | `--cpu` | to disable the GPU (force computations on GPU only) |