Write a command that lists all the files and directories of the current directory, separated by commas (,).
Directory names should end with a slash (/)
Files and directories starting with a dot (.) should be listed
The listing should be alpha ordered, except for the directories . and .. which should be listed at the very beginning
Only digits and letters are used to sort; Digits should come first
You can assume that all the files we will test with will have at least one letter or one digit
The listing should end with a new line