Fix framework multitargeting (#688)

Author: tehcrashxor

src/PAModel/Microsoft.PowerPlatform.Formulas.Tools.csproj

@@ -7,6 +7,13 @@
     <RootNamespace>Microsoft.PowerPlatform.Formulas.Tools</RootNamespace>
   </PropertyGroup>
 
+  <PropertyGroup Label="Override Directory.Build.props Settings">
+    <!-- Clear the singular TargetFramework set by Directory.Build.props, so that it doesn't take precedence over the plural TargetFrameworks set above. -->
+    <TargetFramework></TargetFramework> 
+    <!-- Directory.Build.props sets paths assuming a single Target Framework.  Add the framework to the path to prevent overwriting one with the other -->
+    <OutDir>$(OutDir)\$(TargetFramework)</OutDir>
+  </PropertyGroup>
+
   <!-- Nuget Properties -->
   <PropertyGroup>
     <PackageId>Microsoft.PowerPlatform.Formulas.Tools</PackageId>