chore: Add README and Deprecation notice to DependencyInjection library (#530)

* Add README to DependencyInjection library

* Add deprecation notice in README
* Ensure release-please-config includes extra readme file

Signed-off-by: Kyle Julian <[email protected]>

* Update README to specify v2.9 in deprecated notice

Signed-off-by: Kyle Julian <[email protected]>

---------

Signed-off-by: Kyle Julian <[email protected]>

Author: kylejuliandev

release-please-config.json

@@ -8,7 +8,8 @@
       "versioning": "default",
       "extra-files": [
         "build/Common.prod.props",
-        "README.md"
+        "README.md",
+		    "src/OpenFeature.DependencyInjection/README.md"
       ]
     }
   },

src/OpenFeature.DependencyInjection/OpenFeature.DependencyInjection.csproj

@@ -17,6 +17,7 @@
   <ItemGroup>
     <InternalsVisibleTo Include="$(AssemblyName).Tests" />
     <InternalsVisibleTo Include="DynamicProxyGenAssembly2" />
+    <None Include="../../README.md" Pack="true" PackagePath="/" />
   </ItemGroup>
 
 </Project>

src/OpenFeature.DependencyInjection/README.md

@@ -0,0 +1,48 @@
+# OpenFeature.DependencyInjection
+
+> **⚠️ DEPRECATED**: This library is now deprecated. The OpenTelemetry Dependency Injection library has been moved to the OpenFeature Hosting integration in version 2.9.0.
+
+OpenFeature is an open standard for feature flag management, created to support a robust feature flag ecosystem using cloud native technologies. OpenFeature will provide a unified API and SDK, and a developer-first, cloud-native implementation, with extensibility for open source and commercial offerings.
+
+## Migration Guide
+
+If you are using `OpenFeature.DependencyInjection`, you should migrate to the `OpenFeature.Hosting` package. The hosting package provides the same functionality but in one package.
+
+### 1. Update dependencies
+
+Remove this package:
+
+```xml
+<PackageReference Include="OpenFeature.DependencyInjection" Version="..." />
+```
+
+Update or install the latest `OpenFeature.Hosting` package:
+
+```xml
+<PackageReference Include="OpenFeature.Hosting" Version="2.9.0" />
+```
+
+### 2. Update your `Program.cs`
+
+Remove the `AddHostedFeatureLifecycle` method call.
+
+#### Before
+
+```csharp
+builder.Services.AddOpenFeature(featureBuilder =>
+{
+    featureBuilder
+        .AddHostedFeatureLifecycle();
+
+    // Omit for code brevity
+});
+```
+
+#### After
+
+```csharp
+builder.Services.AddOpenFeature(featureBuilder =>
+{
+    // Omit for code brevity
+});
+```