feat; KTL-1138: add method to generate a link to the playground

[zoobestik]

import { generateCrosslink } from 'kotlin-playground/dist/crosslink';

const link1 = generateCrosslink('println("Hello!")');
// or
const link2 = generateCrosslink('println("Hello!")', {
    targetPlatform: 'JAVA',
    compilerVersion: '1.5.21',
});