handleHelp method
Implementation
void handleHelp(FtpSession session) {
session.sendResponse('214-The following commands are supported:');
session.sendResponse(' USER PASS ACCT QUIT REIN PASV PORT EPSV');
session.sendResponse(' LIST NLST RETR STOR CWD CDUP MKD RMD DELE');
session.sendResponse(' PWD TYPE SIZE FEAT OPTS SYST NOOP ABOR');
session.sendResponse(' MLSD MDTM RNFR RNTO STRU MODE ALLO STAT');
session.sendResponse(' AUTH PBSZ PROT CCC SITE HELP');
session.sendResponse('214 End');
}