Update ServiceStack.Text.Core.csproj

Author: mythz

src/ServiceStack.Text/ServiceStack.Text.Core.csproj

@@ -3,7 +3,7 @@
     <PackageId>ServiceStack.Text.Core</PackageId>
     <AssemblyName>ServiceStack.Text</AssemblyName>
     <RootNamespace>ServiceStack.Text</RootNamespace>
-    <TargetFrameworks>netstandard2.0;netcoreapp2.1</TargetFrameworks>
+    <TargetFrameworks>netstandard2.0;netcoreapp2.1;netstandard2.1</TargetFrameworks>
     <Title>ServiceStack.Text .NET Standard 2.0</Title>
     <PackageDescription>
       .NET's fastest JSON, JSV and CSV Text Serializers. Fast, Light, Resilient.
@@ -13,18 +13,28 @@
     <PackageTags>JSON;Text;Serializer;CSV;JSV;HTTP;Auto Mapping;Dump;Reflection;JS;Utils;Fast</PackageTags>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(TargetFramework)' == 'netcoreapp2.1' ">
-    <DefineConstants>$(DefineConstants);NETSTANDARD2_0;NETCORE2_1</DefineConstants>
+    <DefineConstants>$(DefineConstants);NETSTANDARD;NETCORE2_1</DefineConstants>
   </PropertyGroup>
+  <PropertyGroup Condition=" '$(TargetFramework)' == 'netstandard2.1' ">
+    <DefineConstants>$(DefineConstants);NETSTANDARD;NETSTANDARD2_1</DefineConstants>
+  </PropertyGroup>
+  <ItemGroup>
+    <PackageReference Include="System.Memory" Version="4.5.3" />
+  </ItemGroup>
   <ItemGroup Condition=" '$(TargetFramework)' == 'netstandard2.0' ">
     <PackageReference Include="System.Runtime" Version="4.3.1" />
     <PackageReference Include="Microsoft.CSharp" Version="4.5.0" />
-    <PackageReference Include="System.Memory" Version="4.5.3" />
   </ItemGroup>
   <ItemGroup Condition=" '$(TargetFramework)' == 'netcoreapp2.1' ">
     <PackageReference Include="System.Runtime" Version="4.3.1" />
     <PackageReference Include="System.Reflection.Emit" Version="4.3.0" />
     <PackageReference Include="System.Reflection.Emit.LightWeight" Version="4.3.0" />
     <PackageReference Include="Microsoft.CSharp" Version="4.5.0" />
-    <PackageReference Include="System.Memory" Version="4.5.3" />
+  </ItemGroup>
+  <ItemGroup Condition=" '$(TargetFramework)' == 'netstandard2.1' ">
+    <PackageReference Include="System.Runtime" Version="4.3.1" />
+    <PackageReference Include="System.Reflection.Emit" Version="4.3.0" />
+    <PackageReference Include="System.Reflection.Emit.LightWeight" Version="4.3.0" />
+    <PackageReference Include="Microsoft.CSharp" Version="4.5.0" />
   </ItemGroup>
 </Project>