Adding bash like shell handling

[Retr0Kr0dy]

Added Bourne Again Another Time Shell;
Added command :

• clear
• echo (with stdin working)
• whoami (joke, useless)
• sleep (ms sleep)
• uptime
• grep (with stdin working)
• baatsh

the baatsh command contain the logic to handle :

• && to execute multiple commands (ex: echo a && echo b)
• | to redirect command output to stdin (ex: echo abc | grep b)
• $() to add command output to a command (ex: echo $(whoami))