fix visual issues

src/SUMMARY.md

@@ -28,10 +28,10 @@
 
 - [Choose Your Own Adventure](choice/00.00.README.md)
 
-- [WIP - micro:bit HAL basics](microbit/00.00.README.md)
-  - [WIP - Buttons](microbit/01.00.BUTTONS.md)
-  - [WIP - Delays](microbit/02.00.DELAY.md)
-  - [WIP - Display](microbit/03.00.DISPLAY.md)
+- [micro:bit HAL basics](microbit/00.00.README.md)
+  - [Buttons](microbit/01.00.BUTTONS.md)
+  - [Delays](microbit/02.00.DELAY.md)
+  - [Display](microbit/03.00.DISPLAY.md)
 
 - [WIP - Serial UART](serial/00.00.README.md)
   - [Echo Server](serial/01.00.ECHO.md)

src/microbit/01.00.BUTTONS.md

@@ -6,4 +6,6 @@ The micro:bit as 3 hardware buttons, 2 user buttons and the reset button.
 
 The user buttons are wired up to be high when unpressed and low when pressed.
 
+``` rust
 {{#include examples/buttons.rs}}
+```

src/microbit/03.00.DISPLAY.md

@@ -8,4 +8,6 @@ or for monochrome images with differing brightness levels
 
 ## Blocking binary image display
 
+``` rust
 {{#include examples/display_blocking.rs}}
+```

src/serial/01.02.ECHO.md

@@ -1,3 +1,5 @@
 # Echo Solution
 
+``` rust
 {{#include src/main.rs}}
+```