DOC: Fix segmentation example in script repository

Fix comment format, update variable names, and add missing closing bracket in 'Change file type for saving for existing nodes' section  of script repository.

Docs/developer_guide/script_repository/gui.md

@@ -260,7 +260,7 @@ for volumeNode in volumeNodes:
 To set all volume nodes to save uncompressed by default (add this to [slicerrc.py file](/user_guide/settings.md#application-startup-file) so it takes effect for the whole session):
 
 ```python
-#set the default volume storage to not compress by default
+# Set the default volume storage to not compress by default
 defaultVolumeStorageNode = slicer.vtkMRMLVolumeArchetypeStorageNode()
 defaultVolumeStorageNode.SetUseCompression(0)
 slicer.mrmlScene.AddDefaultNode(defaultVolumeStorageNode)
@@ -270,11 +270,11 @@ logging.info("Volume nodes will be stored uncompressed by default")
 Same thing as above, but applied to all segmentations instead of volumes:
 
 ```python
-#set the default volume storage to not compress by default
-defaultVolumeStorageNode = slicer.vtkMRMLSegmentationStorageNode()
-defaultVolumeStorageNode.SetUseCompression(0)
-slicer.mrmlScene.AddDefaultNode(defaultVolumeStorageNode)
-logging.info("Segmentation nodes will be stored uncompressed
+# Set the default segmentation storage to not compress by default
+defaultSegmentationStorageNode = slicer.vtkMRMLSegmentationStorageNode()
+defaultSegmentationStorageNode.SetUseCompression(0)
+slicer.mrmlScene.AddDefaultNode(defaultSegmentationStorageNode)
+logging.info("Segmentation nodes will be stored uncompressed by default")
 ```
 
 ## Module selection