Add hook and otel4s docs

build.sbt

@@ -238,6 +238,7 @@ lazy val docs = project
   .dependsOn(
     `openfeature-sdk`.jvm,
     `openfeature-sdk-circe`.jvm,
+    `openfeature-sdk-otel4s`.jvm,
     `openfeature-provider-java`.jvm,
     `openfeature-provider-flipt`.jvm
   )

docs/index.md

@@ -111,6 +111,40 @@ def program(features: FeatureClient[IO])(
 Hooks are work-in-progress. All four OpenFeature [hook types](https://openfeature.dev/specification/sections/hooks)
 are supported but only on the `FeatureClient` and `Provider` interfaces.
 
+```scala mdoc
+import cats.effect.IO
+import io.cardell.openfeature.FeatureClient
+import io.cardell.openfeature.BeforeHook
+import io.cardell.openfeature.provider.Provider
+
+val hook = BeforeHook[IO] { case (context, hints @ _) => 
+    IO.println(s"I'm about to evaluate ${context.flagKey}").as(None)
+}
+
+def providerWithHook(provider: Provider[IO]) = 
+    provider.withHook(hook)
+
+// and similarly for `client`
+def clientWithHook(client: FeatureClient[IO]) = 
+    client.withHook(hook)
+```
+
+### otel4s
+
+`otel4s` trace integration is provided, offering a set of trace hooks
+
+```scala mdoc
+import cats.effect.IO
+import org.typelevel.otel4s.trace.Tracer
+import io.cardell.openfeature.FeatureClient
+import io.cardell.openfeature.otel4s.TraceHooks
+
+def tracedClient(
+    client: FeatureClient[IO]
+)(implicit T: Tracer[IO]) = TraceHooks.ioLocal
+    .map(hooks => client.withHooks(hooks))
+```
+
 ### Variants
 
 Providers offer resolving a particular variant, using a Structure type. Typically this is JSON defined on the server side. 

openfeature/sdk/src/main/scala/io/cardell/openfeature/FeatureClient.scala

@@ -27,6 +27,9 @@ trait FeatureClient[F[_]] {
 
   def withHook(hook: Hook[F]): FeatureClient[F]
 
+  def withHooks(hooks: List[Hook[F]]): FeatureClient[F] =
+    hooks.foldLeft(this)(_ withHook _)
+
   def getBooleanValue(flagKey: String, default: Boolean): F[Boolean]
 
   def getBooleanValue(

openfeature/sdk/src/main/scala/io/cardell/openfeature/provider/Provider.scala

@@ -20,6 +20,8 @@ import io.cardell.openfeature.Hook
 
 trait Provider[F[_]] extends EvaluationProvider[F] {
   def withHook(hook: Hook[F]): Provider[F]
-  // def withHooks(hooks: List[Hook[F]]): Provider[F]
+
+  def withHooks(hooks: List[Hook[F]]): Provider[F] =
+    hooks.foldLeft(this)(_ withHook _)
 
 }