chore: add FeatureManagement documentation (#197)

release-please-config.json

@@ -59,7 +59,8 @@
       "bump-patch-for-minor-pre-major": true,
       "versioning": "default",
       "extra-files": [
-        "OpenFeature.Contrib.Providers.FeatureManagement.csproj"
+        "OpenFeature.Contrib.Providers.FeatureManagement.csproj",
+        "README.md"
       ]
     },
     "src/OpenFeature.Contrib.Providers.Statsig": {

src/OpenFeature.Contrib.Providers.FeatureManagement/README.md

@@ -0,0 +1,105 @@
+# FeatureManagement .NET Provider
+> ![NOTE] 
+> This requires a new feature of the FeatureManagement system, Variants. This feature is still in preview and has not been fully released.
+
+The FeatureManagement Provider allows you to use the FeatureManagement system as an OpenFeature Provider.
+
+## .NET SDK Usage
+
+### Install dependencies
+<!--- {x-release-please-start-version} -->
+
+#### .NET Cli
+
+```shell
+dotnet add package OpenFeature.Contrib.Provider.FeatureManagement --version 0.0.1-preview
+```
+
+#### Package Manager
+
+```shell
+NuGet\Install-Package OpenFeature.Contrib.Provider.FeatureManagement -Version 0.0.1-preview
+```
+
+#### Package Reference
+
+```xml
+<PackageReference Include="OpenFeature.Contrib.Provider.FeatureManagement" Version="0.0.1-preview" />
+```
+
+#### Paket CLI
+```shell
+paket add OpenFeature.Contrib.Provider.FeatureManagement --version 0.0.1-preview
+```
+
+#### Cake
+
+```shell
+// Install OpenFeature.Contrib.Provider.FeatureManagement as a Cake Addin
+#addin nuget:?package=OpenFeature.Contrib.Provider.FeatureManagement&version=0.0.1-preview&prerelease
+
+// Install OpenFeature.Contrib.Provider.FeatureManagement as a Cake Tool
+#tool nuget:?package=OpenFeature.Contrib.Provider.FeatureManagement&version=0.0.1-preview&prerelease
+```
+<!--- {x-release-please-end} -->
+
+### Using the FeatureManagement Provider with the OpenFeature SDK
+
+FeatureManagement is built on top of .NETs Configuration system, so you must provide the loaded Configuration.  
+Since Configuration is passed in any valid Configuration source can be used.  
+For simplicity, we'll stick with a json file for all examples.  
+
+```csharp
+namespace OpenFeatureTestApp
+{
+    class Program
+    {
+        static void Main(string[] args)
+        {
+            var configurationBuilder = new ConfigurationBuilder();
+            configurationBuilder.AddJsonFile("featureFlags.json");
+
+            IConfiguration configuration = configurationBuilder.Build();
+
+            var featureManagementProvider = new FeatureManagementProvider(configuration);
+            OpenFeature.Api.Instance.SetProvider(featureManagementProvider);
+
+            var client = OpenFeature.Api.Instance.GetClient();
+
+            var val = await client.GetBooleanValue("myBoolFlag", false, null);
+
+            System.Console.WriteLine(val.ToString());
+        }
+    }
+}
+```
+
+A simple example configuration would look like this.
+
+```json
+{
+  "FeatureManagement": {
+    "myBoolFlag": {
+      "Allocation": {
+        "DefaultWhenEnabled": "FlagEnabled",
+        "DefaultWhenDisabled": "FlagDisabled"
+      },
+      "Variants": [
+        {
+          "Name": "FlagEnabled",
+          "ConfigurationValue": true
+        },
+        {
+          "Name": "FlagDisabled",
+          "ConfigurationValue": false
+        }
+      ],
+      "EnabledFor": [
+        {
+          "Name": "AlwaysOn"
+        }
+      ]
+    }
+  }
+}
+```