Fix an edge case in cmd_as_argument example for empty string after strip

Also:
- Make some documentation more consistent with the example it was referring to

Author: tleonhardt

docs/features/os.md

@@ -120,7 +120,7 @@ example. Using this methodology you can call it like so:
 
     $ uv run examples/argparse_example.py -c blue help
 
-Check the source code of this example, especially the `if __name__ == '__main__':` block, to see the
+Check the source code of this example, especially the `if __name__ == "__main__":` block, to see the
 technique.
 
 ### Automating cmd2 apps from other CLI/CLU tools

examples/cmd_as_argument.py

@@ -50,7 +50,7 @@ def do_speak(self, args) -> None:
         words = []
         for w in args.words:
             word = w.strip()
-            if args.piglatin:
+            if args.piglatin and word:
                 word = f"{word[1:]}{word[0]}ay"
             if args.shout:
                 word = word.upper()