Merge pull request #75 from xypron/readme_add_xorriso_args

README.md: provide name of the add-xorriso-args argument

Author: mwhudson

README.md

@@ -225,7 +225,7 @@ user).
 
 ### add-xorriso-args
 
-**argument**: list of xorriso argument(s)
+**argument**: `xorriso_args` list of xorriso argument(s)
 
 Add one or more extra arguments for `xorriso`, after the ones that
 livefs-editor already supplies.