doc: the claims in security.md need updating to the current purpose of the repository which includes an inventory of community servers

[wherka-ama]

The SECURITY.md in this repo states:

These servers are maintained by Anthropic as part of the Model Context Protocol project.

I think this is a very confusing and in fact misleading claim. It gives people who look at the list of the servers which goes in well over 500 (most of them are community driven) a false sense of security.

One might see it and think - okay, that's covered by Anthropinc - cool! I'm not going to check anything anymore. If something bad happens they will scream at you. It will not be a legal problem of course as it's very easy to point at full description contained in the README etc. Nevertheless, it could be a bit damaging to Anthropic and this community which I deeply care about.

Don't you think it would be better to rephrase it as:

The reference servers in this repo are maintained by Anthropic as part of the Model Context Protocol project.