Create a way to encrypt messages before sending them over the API.

This makes no sense. What encryption standard? How do you exchange keys? There is no way to do ratcheting key exchange with the Discord protocol due to out-of-order message delivery and dropped messages, which means perfect forward secrecy cannot be obtained, so anyone who managers to get a simple pre-shared secret key will be able to decrypt all of your messages. Discord was not designed for end-to-end encryption.

If you want an end-to-end encrypted chat, use something else, like Signal, Keybase, etc.

And don't choose "Important" for off-the-wall feature requests.