note about splitting material

lectures/lecture09/README.md

@@ -20,6 +20,7 @@ After this course, you should be able to:
 - All instructions for this lesson are available in this repository.
   - See the Tutorial section below to get started with the exercises
   - View the introductory presentation by opening the [`slides.html`](slides/slides.html) in a web browser from your local copy of the repository
+  - You are responsible for the material through **Redirection** for this class session; we'll complete the rest of the material in lecture 12.
 - This material requires access to a [unix shell](https://github.com/fredhutchio/tfcb_2019/tree/master/software#unix-command-line). Different "flavors" of shell have slight variations in commands available. These materials are designed to work on a compute cluster at Fred Hutch called rhino. Please see [these instructions](https://github.com/fredhutchio/tfcb_2019/tree/master/software/unix_rhino.md) for logging on to rhino, and note there is an extra step to log in off campus. You can execute most of these commands on your own computer (e.g., without logging in to rhino), but don't be surprised if some of the commands and options are slightly different (especially on OS X).
 
 ## Reminders