chore: modified readme file and added target framework

Directory.Build.props

@@ -2,7 +2,7 @@
 
   <PropertyGroup Label="Versioning">
     <VersionMajor>3</VersionMajor>
-    <VersionMinor>5</VersionMinor>
+    <VersionMinor>6</VersionMinor>
     <VersionPatch>$([System.DateTime]::UtcNow.ToString("MMdd"))</VersionPatch>
     <VersionRevision>$([System.DateTime]::UtcNow.TimeOfDay.TotalMinutes.ToString("0"))</VersionRevision>
     <VersionPrefix>$(VersionMajor).$(VersionMinor).$(VersionPatch).$(VersionRevision)</VersionPrefix>
@@ -29,7 +29,7 @@
     <NeutralLanguage>en-US</NeutralLanguage>
     <Nullable>enable</Nullable>
     <SignAssembly>true</SignAssembly>
-    <TargetFrameworks>netstandard2.0;net462;net481;net8.0;net9.0</TargetFrameworks>
+    <TargetFrameworks>netstandard2.0;netstandard2.1;net462;net481;net8.0;net9.0</TargetFrameworks>
   </PropertyGroup>
 
   <PropertyGroup Condition="'$(Configuration)'=='Release'">

README.md

@@ -7,8 +7,9 @@
 [![NuGet](https://img.shields.io/nuget/v/BB84.Notifications.svg?logo=nuget&logoColor=white)](https://www.nuget.org/packages/BB84.Notifications)
 
 [![net20](https://img.shields.io/badge/netstandard2.0-5C2D91?logo=.NET&labelColor=gray)](https://github.com/BoBoBaSs84/BB84.Notifications)
+[![net21](https://img.shields.io/badge/netstandard2.1-5C2D91?logo=.NET&labelColor=gray)](https://github.com/BoBoBaSs84/BB84.Notifications)
 [![net462](https://img.shields.io/badge/net462-5C2D91?logo=.NET&labelColor=gray)](https://github.com/BoBoBaSs84/BB84.Notifications)
-[![net48](https://img.shields.io/badge/net48-5C2D91?logo=.NET&labelColor=gray)](https://github.com/BoBoBaSs84/BB84.Notifications)
+[![net481](https://img.shields.io/badge/net481-5C2D91?logo=.NET&labelColor=gray)](https://github.com/BoBoBaSs84/BB84.Notifications)
 [![net80](https://img.shields.io/badge/net8.0-5C2D91?logo=.NET&labelColor=gray)](https://github.com/BoBoBaSs84/BB84.Notifications)
 [![net90](https://img.shields.io/badge/net9.0-5C2D91?logo=.NET&labelColor=gray)](https://github.com/BoBoBaSs84/BB84.Notifications)