Changed ls -al to the more common ls -la (#23)

Author: borekb

README.md

@@ -199,7 +199,7 @@ ls option
 ```
 Example:
 <pre>
-$ ls -al
+$ ls -la
 rwxr-xr-x 33 adnan staff 1122 Mar 27 18:44 .
 drwxrwxrwx 60 adnan staff 2040 Mar 21 15:06 ..
 -rw-r--r--@ 1 adnan staff 14340 Mar 23 15:05 .DS_Store