Add SL2 disclaimer to readme and package description

Related to #126

Author: kzu

readme.md

@@ -6,6 +6,8 @@
 [![License](https://img.shields.io/github/license/devlooped/DependencyInjection.Attributed.svg?color=blue)](https://github.com//devlooped/DependencyInjection.Attributed/blob/main/license.txt)
 [![Build](https://github.com/devlooped/DependencyInjection.Attributed/workflows/build/badge.svg?branch=main)](https://github.com/devlooped/DependencyInjection.Attributed/actions)
 
+<!-- include https://github.com/devlooped/.github/raw/main/sponsorlinkr.md -->
+
 <!-- #content -->
 
 Automatic compile-time service registrations for Microsoft.Extensions.DependencyInjection with no run-time dependencies, 

src/DependencyInjection/readme.md

@@ -1,4 +1,5 @@
-<!-- include ../../readme.md#content -->
+<!-- include https://github.com/devlooped/.github/raw/main/sponsorlinkr.md -->
+<!-- include ../../readme.md#content -->
 <!-- include https://github.com/devlooped/sponsors/raw/main/footer.md -->
 <!-- Exclude from auto-expansion in CI -->
 <!-- exclude -->

src/Directory.targets

@@ -1,5 +1,14 @@
 <Project InitialTargets="SetLocalVersion">
 
+  <PropertyGroup>
+    <Description>
+      $(Description)
+
+      > This project uses SponsorLink to attribute sponsor status (direct, indirect or implicit). For IDE usage, sponsor status is required.
+      > IDE-only warnings will be emitted after a grace period otherwise. Learn more at https://github.com/devlooped#sponsorlink.
+    </Description>
+  </PropertyGroup>
+
   <Target Name="SetLocalVersion" Condition="!$(CI)">
     <GetVersion>
       <Output TaskParameter="Version" PropertyName="Version" />