Add /weeelcome command

[e-caste]

When a new member joins the team, use this command to add them to the team's Telegram groups. Everyone should be added by default to the announcements and chat groups, but it should be possible to select, with an interactive keyboard:

• [ ] all the locked accounts that have recently had (e.g. today - dateofsafetytest <= 7 days) and, in a submenu:
• [ ] A button for the 2 default groups, plus a button for each of the optional / topic-oriented Telegram groups. The selected button should update accordingly, with a ✅ to indicate that the user has been added to a group, and a ❌ to indicate that the user is not / has been removed from that group.

This should be done by updating a reply_keyboard object, and every menu should include a Close button. The groups submenu should have a back button, to select other people.
This command should be reserved to bot admins.

[e-caste]

See this stackoverflow question for more details. There is no API to do exactly what this issue says, but the bot can still send group invite links, if the user has started it in a private chat. Also, read the docs here