[MERGE #6166 @MikeHolman] add ChakraCoreWindows.h to nuget include path

Merge pull request #6166 from MikeHolman:nugetinclude

Header for Windows specific JSRT APIs, currently needed for `JsConnectJITProcess`

Author: MikeHolman

Build/NuGet/Microsoft.ChakraCore.vc140.nuspec

@@ -24,6 +24,7 @@
     <file src="..\..\lib\Jsrt\ChakraCommon.h" target="build\native\include\ChakraCommon.h"/>
     <file src="..\..\lib\Jsrt\ChakraCommonWindows.h" target="build\native\include\ChakraCommonWindows.h"/>
     <file src="..\..\lib\Jsrt\ChakraCore.h" target="build\native\include\ChakraCore.h"/>
+    <file src="..\..\lib\Jsrt\ChakraCoreWindows.h" target="build\native\include\ChakraCoreWindows.h"/>
     <file src="..\..\lib\Jsrt\ChakraDebug.h" target="build\native\include\ChakraDebug.h"/>
 
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