typescript+es6 support

[sirpy]

trying to integrate with webcrypto-liner and other libraries
can you help out by setting your project to support typescript + es6?

[kevlened]

Hmm, I'm unsure what setting this library to typescript + es6 would mean and how it would help integrate with other WebCrypto libraries.

vscode should automatically import types from libraries that export them, even with commonjs. We export index.d.js to ensure other projects get types when they import isomorphic-webcrypto.

[sirpy]

we need to add precompiler like babel. otherwise it would require rewriting code we want to reuse that is in ts or es6