hacking-on-atom-core.md: Update windows info

Visual Studio 2015, 2017 and 2019 are supported.
Windows 8 SDK or Windows 10 SDK are supported.
Clarified windows-build-tools install instructions.
The latest windows-build-tools will be fine for the foreseeable future
(Even when they default to Visual Studio 2019 some time soon.)

content/hacking-atom/sections/hacking-on-atom-core.md

@@ -97,18 +97,18 @@ In order to build Atom from source, you need to have a number of other requireme
   * The `python.exe` must be available at `%SystemDrive%\Python27\python.exe`. If it is installed elsewhere create a symbolic link to the directory containing the `python.exe` using: `mklink /d %SystemDrive%\Python27 D:\elsewhere\Python27`
 * 7zip (7z.exe available from the command line) - for creating distribution zip files
 * C++ build tools, either:
-  * [Visual C++ Build Tools 2015 or newer](https://visualstudio.microsoft.com/visual-cpp-build-tools/)
-  * [Visual Studio 2015 or newer](https://www.visualstudio.com/downloads/) (Community Edition or better)
-  * [windows-build-tools](https://www.npmjs.com/package/windows-build-tools): `npm install --global --production windows-build-tools@4.0`
+  * [Visual C++ Build Tools 2015, 2017 or 2019](https://visualstudio.microsoft.com/visual-cpp-build-tools/)
+  * [Visual Studio 2015, 2017 or 2019](https://www.visualstudio.com/downloads/) (Community Edition or better)
+  * [windows-build-tools](https://www.npmjs.com/package/windows-build-tools) (From an elevated CMD.exe or Powershell window (right click and "run as Administrator") do: `npm install --global --production windows-build-tools` to install)
 
 
   Also ensure that:
 
   * The default installation folder is chosen so the build tools can find it
   * If using Visual Studio make sure Visual C++ support is selected/installed
-  * If using Visual C++ Build Tools make sure a Windows SDK is selected/installed
+  * If using Visual C++ Build Tools make sure a Windows SDK (Windows 8 SDK or Windows 10 SDK) is selected/installed
   * A `git` command is in your path
-  * Set the `GYP_MSVS_VERSION` environment variable to the Visual Studio/Build Tools version (`2015`, `2017`, etc.) e.g. ``[Environment]::SetEnvironmentVariable("GYP_MSVS_VERSION", "2015", "User")`` in PowerShell (or set it in Windows advanced system settings).
+  * Set the `GYP_MSVS_VERSION` environment variable to the Visual Studio/Build Tools version (`2015`, `2017`, or `2019`.) e.g. ``[Environment]::SetEnvironmentVariable("GYP_MSVS_VERSION", "2015", "User")`` in PowerShell (or set it in Windows advanced system settings).
 
 {{/windows}}