[Feature request] More tools to fight spams
We recently had a wave of elaborate spammers on both reddit and the forum.

Their question elicit good answers that are unfortunately lost to the community and Google after those spammer edit the links.

Examples:

- https://forum.nim-lang.org/t/5676
- https://forum.nim-lang.org/t/5675

I have 3 ideas to prevent that:
- Allow admins to lock a message for edition
- Lock messages for editions after a day as long as the original poster doesn't meet a certain bar (like 5 posts which ought to be enough to detect genuineness)
- Don't allow links or editing links in besides a whitelist (playground, github, gitlab, bitbucket, ix.io, pastebins, ...) if someone has less than 2 posts.

The first one should probably be there while the 2 and 3 are probably either one or the other.