doc: add windows-build-tools to readme

Added Microsoft's [windows-build-tools](https://github.com/felixrieseberg/windows-build-tools) to the readme.

PR-URL: #970
Reviewed-By: João Reis <reis@janeasystems.com>

README.md

@@ -42,15 +42,17 @@ You will also need to install:
       * You also need to install the `Command Line Tools` via Xcode. You can find this under the menu `Xcode -> Preferences -> Downloads`
       * This step will install `gcc` and the related toolchain containing `make`
   * On Windows:
-    * Visual C++ Build Environment:
-      * Option 1: Install [Visual C++ Build Tools](http://landinghub.visualstudio.com/visual-cpp-build-tools) using the **Default Install** option.
+    * Option 1: Install all the required tools and configurations using Microsoft's [windows-build-tools](https://github.com/felixrieseberg/windows-build-tools) using `npm install --global --production windows-build-tools` from an elevated PowerShell or CMD.exe (run as Administrator).
+    * Option 2: Install tools and configuration manually:
+      * Visual C++ Build Environment:
+        * Option 1: Install [Visual C++ Build Tools](http://landinghub.visualstudio.com/visual-cpp-build-tools) using the **Default Install** option.
 
-      * Option 2: Install [Visual Studio 2015](https://www.visualstudio.com/products/visual-studio-community-vs) (or modify an existing installation) and select *Common Tools for Visual C++* during setup. This also works with the free Community and Express for Desktop editions.
+        * Option 2: Install [Visual Studio 2015](https://www.visualstudio.com/products/visual-studio-community-vs) (or modify an existing installation) and select *Common Tools for Visual C++* during setup. This also works with the free Community and Express for Desktop editions.
 
-      > :bulb: [Windows Vista / 7 only] requires [.NET Framework 4.5.1](http://www.microsoft.com/en-us/download/details.aspx?id=40773)
+        > :bulb: [Windows Vista / 7 only] requires [.NET Framework 4.5.1](http://www.microsoft.com/en-us/download/details.aspx?id=40773)
 
-    * Install [Python 2.7](https://www.python.org/downloads/) (`v3.x.x` is not supported), and run `npm config set python python2.7` (or see below for further instructions on specifying the proper Python version and path.)
-    * Launch cmd, `npm config set msvs_version 2015`
+      * Install [Python 2.7](https://www.python.org/downloads/) (`v3.x.x` is not supported), and run `npm config set python python2.7` (or see below for further instructions on specifying the proper Python version and path.)
+      * Launch cmd, `npm config set msvs_version 2015`
 
     If the above steps didn't work for you, please visit [Microsoft's Node.js Guidelines for Windows](https://github.com/Microsoft/nodejs-guidelines/blob/master/windows-environment.md#compiling-native-addon-modules) for additional tips.