Mention `-c` option in README

README.md

@@ -43,6 +43,7 @@ By default, gotty starts a web server at port 8080. Open the URL on your web bro
 --addr, -a           IP address to listen [$GOTTY_ADDR]
 --addr, -a           IP address to listen [$GOTTY_ADDR]
 --port, -p "8080"    Port number to listen [$GOTTY_PORT]
 --port, -p "8080"    Port number to listen [$GOTTY_PORT]
 --permit-write, -w   Permit clients to write to the TTY (BE CAREFUL) [$GOTTY_PERMIT_WRITE]
 --permit-write, -w   Permit clients to write to the TTY (BE CAREFUL) [$GOTTY_PERMIT_WRITE]
+--credential, -c     Credential for Basic Authentication (ex: user:pass) [$GOTTY_CREDENTIAL]
 ```
 ```
 
 
 By default, gotty doesn't allow clients to send any keystrokes or commands except terminal window resizing. When you want to permit clients to write input to the PTY, add the `-w` option. However, accepting input from remote clients is dangerous for most commands. Make sure that only trusted clients can connect to your gotty server when you activate this option. If you need interaction with the PTY, consider starting gotty with tmux or GNU Screen and run your main command on it.
 By default, gotty doesn't allow clients to send any keystrokes or commands except terminal window resizing. When you want to permit clients to write input to the PTY, add the `-w` option. However, accepting input from remote clients is dangerous for most commands. Make sure that only trusted clients can connect to your gotty server when you activate this option. If you need interaction with the PTY, consider starting gotty with tmux or GNU Screen and run your main command on it.