Make the installation scripts install Node and tns

[tjvantoll]

Currently our recommended quick installation is a three-step process: install Node, install tns, and then run our setup scripts. Even though those steps are relatively minimal, a surprising number of people get tripped up going through them. See https://github.com/NativeScript/docs/pull/585 for an example.

I want to propose that we change the installation scripts to install everything—Node, tns, and the various system requirements. The scripts could detect whether Node is installed, as to avoid undoing a user’s installation unknowingly.

A single script would simplify the documentation considerably, but it would probably be a non-trivial engineering effort. And with installers in the works perhaps this isn’t worth the effort. But I wanted to open this up to see what people think.

Thoughts?

[donangel]

Let me try to describe how a brand new "setup process" goes on a new Windows machine.

For me, I do the following:

1. Install Chocolatey
2. Either manually, or via script, install Node, Visual Studio Code, Java SE, Android SDK. Sometimes the SDK is already deployed by Visual Studio 2015 Community installation (I am not religious about this, my problem is that it almost never sets up correctly the environment variables).
3. Install NativeScript. Usually, during this installation it'll start failing with errors, related to non-existing ENV, which I fix one by one.

To me, it'll be of a tremendous help, if there's also Chocolatey package, related to {N}.