兼容小程序运行环境的 sha256 实现
npm install weapp-sha256 --save
import { sha256 } from 'weapp-sha256';
sha256('hello'); // "2cf24dba5fb0a30e26e83b2ac5b9e29e1b161e5c1fa7425e73043362938b9824" <= Hex-encoded; default
sha256('hello', { asBytes: true }); // [44,242,77,186,95,176,163,14,38,232,59,42,197,185,226,158,27,22,30,92,31,167,66,94,115,4,51,98,147,139,152,36] <= Array of bytes