Examples in README contain errors

[Karting06]

Hi,

For your information, when migrating to version 3, I noticed that the README is wrong.

It should be Utf8 instead of UTF8 (same for PKCS7 that should be Pkcs7):

The following doesn't work:

import { Base64, Hex, UTF8 } from 'crypto-es';

import { AES, CBC, PKCS7 } from 'crypto-es';

This works:

import { Base64, Hex, Utf8 } from 'crypto-es';

import { AES, CBC, Pkcs7 } from 'crypto-es';

Which makes sense since Utf8 is exported here.

Thanks for the package,