Update config_spec.md
Update default behavior for `loader`
@@ -194,10 +194,8 @@ See also: [Patch-base analysis guide](./window_sizes.html)
###### `loader`
Specify the loader to be used to load the files in the input section.
Some loaders require additional Python packages.
-Default value `None` indicates trying all available loaders.
-
-Supported loaders: `nibabel`, `opencv`, `skimage`, `pillow`, `simpleitk`, `dummy`
-in prioriy order.
+Supported loaders: `nibabel`, `opencv`, `skimage`, `pillow`, `simpleitk`, `dummy` in prioriy order.
+Default value `None` indicates trying all available loaders, in the above priority order.
This section will be used by [ImageReader](./niftynet.io.image_reader.html)
to generate a list of [input images objects](./niftynet.io.image_type.html).
