feat: implement blacklist

[Helias]

blacklist anti-spam

[TendTo]

Apart from what I have already commented, I would also add the new feature to the changelog and the new setting parameter to the README, in the Settings section

---

This said, there are a few considerations I would like to add about the feature itself.
I personally don't really like this kind of heavy-handed moderation. A telegram group already provides all the tools the moderators may use to ban or limit a misbehaving user.

Even worse, I feel like this measure is just going to create more trouble than it solves. Since you are just checking a substring in the message, it would be extremely easy for anyone to avoid the check or, alternately, for an unsuspecting user to see their message deleted just because they used a specific word or expression. Just think about the many asterisks that appear on online chats all the time a word contains any "dangerous" substring. In our case they would just lose the message without any way of recovering it.

I don't know what circumstance made you think of this feature, but I strongly advise against its implementation, especially in the current form.

[Helias]

I don't know what circumstance made you think of this feature, but I strongly advise against its implementation, especially in the current form.

I totally agree, it's more an anti-spam feature than a moderation tool, in these days we are experiencing a spam about a telegram channel about a black market that we would like to prevent

I don't think that the user who spams it, is so smart to understand that we are doing this feature and avoid it.

It's only an anti-spam feature, nothing related to the spotted community