change TargetFramework to netstandard

Author: Amin GolMahaleh

src/HttpClientToCurl/HttpClientToCurl.csproj

@@ -4,9 +4,10 @@
         <Authors>Amin Golmahalleh</Authors>
         <Version>1.8.4</Version>
         <PackageReleaseNotes>1.8.4</PackageReleaseNotes>
-        <TargetFramework>net7.0</TargetFramework>
+        <TargetFramework>netstandard2.1</TargetFramework>
         <ImplicitUsings>enable</ImplicitUsings>
         <Nullable>disable</Nullable>
+        <LangVersion>11</LangVersion>
     </PropertyGroup>
 
     <ItemGroup>