telethon add members to group python code example

Example: telethon invite to group

# public chat
from telethon.tl.functions.channels import JoinChannelRequest
await client(JoinChannelRequest(channel))

# private chat
from telethon.tl.functions.messages import ImportChatInviteRequest
updates = await client(ImportChatInviteRequest('AAAAAEHbEkejzxUjAUCfYg'))