updating docs

CHANGELOG.md

@@ -8,7 +8,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ## Unreleased
 ### Added
 
-- `opentelemetry-instrumentation-pika` Instrumentation for `channel.consume()` function 
+- `opentelemetry-instrumentation-pika` Instrumentation for `channel.consume()` (supported
+  only for global, non channel specific instrumentation)
   ([#2397](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/2397)))
 
 ### Breaking changes

instrumentation/opentelemetry-instrumentation-pika/src/opentelemetry/instrumentation/pika/__init__.py

@@ -77,6 +77,15 @@ def consume_hook(span: Span, body: bytes, properties: BasicProperties):
 
     PikaInstrumentor.instrument_channel(channel, publish_hook=publish_hook, consume_hook=consume_hook)
 
+Consumer Instrumentation
+-----
+For consumer instrumentation, pika supports two consuming modes:
+
+* Consumers using the `basic_consume` method which accepts a callback. This is supported for global instrumentation
+  (`PikaInstrumentor().instrument()`) as well channel specific instrumentation (`PikaInstrumentor().instrument_channel(channel)`)
+* Consumers using the `consume` method which returns a generator over messages. This is supported for global
+  instrumentations only (`PikaInstrumentor().instrument()`)
+
 API
 ---
 """