More fixes.

exercise-book/src/nrf52-usb-data-stage.md

@@ -22,6 +22,8 @@ Extend `usb-3.rs` so that it uses `Ep0In` to respond to the `GET_DESCRIPTOR Devi
 
 ### Values of the device descriptor
 
+The raw values you need to pack into the descriptor are as follows. Note, we won't be doing this by hand, so read on before you start typing!
+
 - `bLength = 18`, the size of the descriptor (must always be this value)
 - `bDescriptorType = 1`, device descriptor type (must always be this value)
 - `bDeviceClass = bDeviceSubClass = bDeviceProtocol = 0`, these are unimportant for enumeration

exercise-book/src/nrf52-usb-setup-stage.md

@@ -22,7 +22,7 @@ Modify `Request::parse()` in `nrf52-code/usb-lib/src/lib.rs` to recognize a `GET
 
 When you need to write some `no_std` code that does not involve device-specific I/O you should consider writing it as a separate crate. This way, you can test it on your development machine (e.g. `x86_64`) using the standard `cargo test` functionality.
 
-So that's what we'll do here. In `nrf52-code/usb-lib/src/lib.rs` you'll find starter code for writing a `no_std` SETUP data parser. The starter code contains some unit tests; you can run them with `cargo test` (from within the `usb` folder) or you can use Rust Analyzer's "Test" button in VS code.
+So that's what we'll do here. In `nrf52-code/usb-lib/src/lib.rs` you'll find starter code for writing a `no_std` SETUP data parser. The starter code contains some unit tests; you can run them with `cargo test` (from within the `usb-lib` folder) or you can use Rust Analyzer's "Test" button in VS code.
 
 The definition of `Descriptor::Configuration` as well as the associated test has been "commented out" using an `#[cfg(TODO)]` attribute because it is not handled by the firmware yet. Delete the `#[cfg(TODO)]` so that the unit tests can access it. This pattern is used for enum members and test functions throughout this workshop, so keep it in mind should you see it again.