/start

Welcomes everyone that enters a group chat that this bot is a part of. By default, only the person who invited the bot into the group is able to change settings.
Commands:

/welcome - Set welcome message
/goodbye - Set goodbye message
/disable_goodbye - Disable the goodbye message
/lock - Only the person who invited the bot can change messages
/unlock - Everyone can change messages
/quiet - Disable "Sorry, only the person who..." & help messages
/unquiet - Enable "Sorry, only the person who..." & help messages

You can use $username and $title as placeholders when setting messages. HTML formatting is also supported.