Typescript

[tswistak]

Hi,

I think it covers 99% of SunEditor use cases in TypeScript.

1. I've reverted d.ts files you've deleted. Though they are not imported directly by the user, it allowed to split typings code into smaller parts. And we need them, because whole functionality is inside lib/core. We can merge everything into one file (like index.d.ts) but it would be hard to maintain manually.
2. In some cases I couldn't guess the type, so I've left any with TODO comment.
3. To consider - maybe we don't need full typing for Lang, maybe just Record<string, string> would be enough.

Cheers!