Switching symbols to be generated as snupkg to be uploaded to NuGet (#568)

Directory.Build.targets

@@ -17,6 +17,10 @@
 
   <!-- Packaging Targets -->
   <PropertyGroup>
+    <!-- Generate snupkg package -->
+    <IncludeSymbols>true</IncludeSymbols>
+    <SymbolPackageFormat>snupkg</SymbolPackageFormat>
+    <!-- Collect package assets from builds -->
     <IncludeRIDSpecificBuildOutput Condition="'$(IncludeRIDSpecificBuildOutput)' == '' And '$(RuntimeIdentifiers)' != ''">true</IncludeRIDSpecificBuildOutput>
     <TargetsForTfmSpecificContentInPackage Condition="'$(IncludeRIDSpecificBuildOutput)' == 'true'">
       $(TargetsForTfmSpecificContentInPackage);