FrameProcessor: add push_interruption_task_frame_and_wait()

CHANGELOG.md

@@ -9,6 +9,17 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Added
 
+- Added `FrameProcessor.push_interruption_task_frame_and_wait()`. Use this
+  method to programatically interrupt the bot from any part of the
+  pipeline. This guarantees that all the processors in the pipeline are
+  interrupted in order (from upstream to downstream). Internally, this works by
+  first pushing an `InterruptionTaskFrame` upstream until it reaches the
+  pipeline task. The pipeline task then generates an `InterruptionFrame`, which
+  flows downstream through all processors. Once the `InterruptionFrame` has
+  reaches the processor waiting for the interruption, the function returns and
+  execution continues after the call. Think of it as sending an upstream request
+  for interruption and waiting until the acknowledgment flows back downstream.
+
 - Added new base `TaskFrame` (which is a system frame). This is the base class
   for all task frames (`EndTaskFrame`, `CancelTaskFrame`, etc.) that are meant
   to be pushed upstream to reach the pipeline task.