Add Typescript examples in Nodejs SDK

Since Node.js SDK 3.2 has support for Typescript now, we should start adding examples in our documentation.

To start off we could have an example in the Getting Started page where users can see the equivalent Typescript version of existing JS code.

Some information on how to setup their environment to use Typescript may be useful also.

Ultimately it will be good to have most of our JS examples to show their Typescript counterparts.