How to support sr25519 in addFromMnemonic()?

[raqeta]

How to support sr25519 in addFromMnemonic()?

[leonardocustodio]

We have just released sr25519 support this week.

Here is a simple sample of how to create a keypair using sr25519

import 'package:polkadart_keyring/polkadart_keyring.dart';

final keyring = await KeyPair.sr25519.fromMnemonic("my seed phrase stay here");
keyring.ss58Format = 1110;
final publicKey = hex.encode(keyring.publicKey.bytes);
print('Public Key: $publicKey');
print('Encoded address: ${keyring.address}');