adding ContinuousIntegrationBuild to project

using netstandard for building instead of coreapp

Author: matt-lethargic

src/GeoJSON.Text.Test.Benchmark/GeoJSON.Text.Test.Benchmark.csproj

@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-	<TargetFrameworks>netcoreapp3.1;net5;net6</TargetFrameworks>
+	<TargetFrameworks>netstandard2.0;net5;net6</TargetFrameworks>
     <ImplicitUsings>disable</ImplicitUsings>
     <Nullable>enable</Nullable>
     <SignAssembly>False</SignAssembly>

src/GeoJSON.Text/GeoJSON.Text.csproj

@@ -1,12 +1,12 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
 	<PropertyGroup>
-		<TargetFrameworks>netcoreapp3.1;net5;net6</TargetFrameworks>
+		<TargetFrameworks>netstandard2.0;net5;net6</TargetFrameworks>
 		<LangVersion>Latest</LangVersion>
 		<Description>.Net types for the GeoJSON RFC to be used with System.Text.Json</Description>
 		<Authors>Matt Hunt</Authors>
 		<Company>GeoJSON.Text</Company>
-		<Copyright>Copyright © Matt Hunt, Xavier Fischer and Contributors, 2014 - 2021</Copyright>
+		<Copyright>Copyright © Matt Hunt  and Contributors, 2014 - 2021</Copyright>
 		<GeneratePackageOnBuild>true</GeneratePackageOnBuild>
 		<Version>0.1.0</Version>
 		<PackageProjectUrl>https://github.com/GeoJSON-Net/GeoJSON.Text</PackageProjectUrl>
@@ -22,6 +22,10 @@
 		<PublishRepositoryUrl>true</PublishRepositoryUrl>
 	</PropertyGroup>
 
+	<PropertyGroup Condition="'$(GITHUB_ACTIONS)' == 'true'">
+		<ContinuousIntegrationBuild>true</ContinuousIntegrationBuild>
+	</PropertyGroup>	
+
 	<ItemGroup>
 		<PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.1.1" PrivateAssets="All" />
 		<PackageReference Include="System.Text.Json" Version="6.0.1" />