nostr package, readme updates accordingly, matching example program (#14)

keys.go

@@ -1,39 +0,0 @@
-package nostr
-
-import (
-	"crypto/rand"
-	"encoding/hex"
-	"io"
-	"math/big"
-
-	"github.com/btcsuite/btcd/btcec/v2"
-	"github.com/btcsuite/btcd/btcec/v2/schnorr"
-)
-
-func GeneratePrivateKey() string {
-	params := btcec.S256().Params()
-	one := new(big.Int).SetInt64(1)
-
-	b := make([]byte, params.BitSize/8+8)
-	_, err := io.ReadFull(rand.Reader, b)
-	if err != nil {
-		return ""
-	}
-
-	k := new(big.Int).SetBytes(b)
-	n := new(big.Int).Sub(params.N, one)
-	k.Mod(k, n)
-	k.Add(k, one)
-
-	return hex.EncodeToString(k.Bytes())
-}
-
-func GetPublicKey(sk string) (string, error) {
-	b, err := hex.DecodeString(sk)
-	if err != nil {
-		return "", err
-	}
-
-	_, pk := btcec.PrivKeyFromBytes(b)
-	return hex.EncodeToString(schnorr.SerializePubKey(pk)), nil
-}