AppVeyor: Initial support

Signed-off-by: Simon Rozman <simon@rozman.si>

README.md

@@ -1,4 +1,4 @@
-# WinStd
+# WinStd [![Build status](https://ci.appveyor.com/api/projects/status/1e8868i88s10cp59?svg=true)](https://ci.appveyor.com/project/Amebis/winstd)
 
 Provides additional templates and function helpers for Windows API using Standard C++
 

appveyor.yml

@@ -0,0 +1,18 @@
+version: 1.0.{build}
+environment:
+  matrix:
+    - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2017
+      PROJECT_FILE: WinStd-15.0.sln
+    - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2019
+      PROJECT_FILE: WinStd-16.0.sln
+configuration:
+  - Debug
+  - Release
+platform:
+  - Win32
+  - x64
+  - ARM64
+build:
+  project: $(PROJECT_FILE)
+  parallel: true
+  verbosity: minimal