Add warning for undefined 'e' in signSchnorr function (#3)

This commit introduces a console warning when 'e' (auxRand equivalent) is undefined during a Schnorr signing operation. The warning informs users of potential discrepancies between our library and tiny-secp256k1 due to differences in how 'e' is handled when it's not provided. This is a response to issue #3.

index.js

@@ -310,7 +310,12 @@ export function sign(h, d, e) {
   return necc.signSync(h, d, { der: false, extraEntropy: e });
 }
 
-export function signSchnorr(h, d, e = Buffer.alloc(32, 0x00)) {
+export function signSchnorr(h, d, e) {
+  if (e === undefined) {
+    console.warn(
+      `Warning: The extra data 'e' is not defined. This library defaults to a random value when 'e' is undefined, which is different from the deterministic approach in tiny-secp256k1. This might lead to discrepancies in the Schnorr signatures between the two libraries.`
+    );
+  }
   if (!isPrivate(d)) {
     throw new Error('Expected Private');
   }

package.json

@@ -1,7 +1,7 @@
 {
   "name": "@bitcoinerlab/secp256k1",
   "homepage": "https://bitcoinerlab.com/secp256k1",
-  "version": "1.0.2",
+  "version": "1.0.3",
   "description": "A library for performing elliptic curve operations on the secp256k1 curve. It is designed to integrate into the BitcoinJS & BitcoinerLAB ecosystems and uses the audited noble-secp256k1 library. It is compatible with environments that do not support WASM, such as React Native.",
   "main": "dist/index.js",
   "types": "types/index.d.ts",