Appveyor (#91)

* add appveyor config

* badge

* minor tweak

* modify ignore list.

* include package lock

* correct build step

* final tweaks to appveyor build

* update readme.

* typo

Author: omniomi

.gitignore

@@ -1,3 +1,2 @@
 syntaxes/
-tools/node_modules/
-tools/package-lock.json
+tools/node_modules/

README.md

@@ -1,4 +1,4 @@
-[![Join the chat at https://gitter.im/PowerShell/EditorSyntax](https://badges.gitter.im/PowerShell/EditorSyntax.svg)](https://gitter.im/PowerShell/EditorSyntax?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
+[![Build status](https://ci.appveyor.com/api/projects/status/github/powershell/editorsyntax?branch=master&svg=true)](https://ci.appveyor.com/project/powershell/editorsyntax/branch/master) [![Join the chat at https://gitter.im/PowerShell/EditorSyntax](https://badges.gitter.im/PowerShell/EditorSyntax.svg)](https://gitter.im/PowerShell/EditorSyntax?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
 
 # PowerShell Syntax Definition for Editors
 
@@ -24,6 +24,8 @@ for more details.
 
 ## Build and Import (VS Code)
 
+> ***NOTE:*** You can grab a build of the current definitions as they exist in Github from [Appveyor](https://ci.appveyor.com/project/powershell/editorsyntax/branch/master/artifacts) and skip ahead to step 3 below.
+
 ### Prerequisites
 
 - Node.JS, >= 8.9.1

appveyor.yml

@@ -0,0 +1,32 @@
+version: 1.0.{build}
+image: Visual Studio 2017
+skip_tags: true
+
+branches:
+  only:
+  - master
+  - development
+  - appveyor
+
+pull_requests:
+  do_not_increment_build_number: true
+
+skip_commits:
+  message: /skip\-build/
+  files:
+    - .vscode/
+    - README.md
+    - .gitattributes
+    - .gitignore
+
+install:
+  - ps: Install-Product node '8.9.1'
+  - ps: Set-Location (Join-Path $env:APPVEYOR_BUILD_FOLDER '\tools\')
+  - ps: npm install
+
+build_script:
+  - ps: Set-Location (Join-Path $env:APPVEYOR_BUILD_FOLDER '\tools\')
+  - ps: npm run build-grammar
+
+on_finish:
+  - ps: Push-AppveyorArtifact (Join-Path $env:APPVEYOR_BUILD_FOLDER '\syntaxes\powershell.tmLanguage.json')