FAQ should mention sealed boxes

[plujon]

https://github.com/RubyCrypto/rbnacl/wiki/Frequently-Asked-Questions states:

Q: Is there any way to decrypt a Crypto::Box message with only a private key without requiring the public key of the sender?

A: No, and there never will be. This is an integral part of how the Curve25519 algorithm operates, and the mutual authentication it provides is a design principle you should consider whenever using public key cryptography.

A SealedBox allows one to decrypt a box with only a private key and without the public key of the sender, does it not? Do I misunderstand what this FAQ is about?

[tarcieri]

Yes, the FAQ is wrong there. Want to open a PR?

[plujon]

Sorry, I'm a little clueless as far as github goes. Is it possible to open a PR against a github wiki page?