Update unarchive.py - Further clarify extra_opts (#58102)

* Update unarchive.py - Further clarify extra_opts
Update the description in the options to help assist with what the module is looking for in the extra_opts.  #31873 alone is not enough since if you are not familiar with the option given in the example it may not be obvious that both elements are part of the same option instead of being two different options.

Co-Authored-By: Alicia Cozine <879121+acozine@users.noreply.github.com>

lib/ansible/modules/files/unarchive.py

@@ -72,6 +72,8 @@ options:
   extra_opts:
     description:
       - Specify additional options by passing in an array.
+      - Each space-separated command-line option should be a new element of the array. See examples.
+      - Command-line options with multiple elements must use multiple lines in the array, one for each element.
     type: list
     default: ""
     version_added: "2.1"