Link fixes, thanks CI!

src/start/index.md

@@ -8,7 +8,7 @@ In this section we'll walk you through the process of writing, building,
 flashing and debugging embedded programs. You will be able to try most of the
 examples without any special hardware as we will show you the basics using
 QEMU, a popular open-source hardware emulator. The only section where hardware
-is required is, naturally enough, the [Hardware](start/hardware.md) section,
+is required is, naturally enough, the [Hardware](./hardware.md) section,
 where we use OpenOCD to program an [STM32F3DISCOVERY].
 
 [STM32F3DISCOVERY]: http://www.st.com/en/evaluation-tools/stm32f3discovery.html

src/start/registers.md

@@ -13,7 +13,7 @@ You may well find that the code you need to access the peripherals in your micro
 [tm4c123x]: https://crates.io/crates/tm4c123x
 [stm32f30x]: https://crates.io/crates/stm32f30x
 [embedded-hal]: https://crates.io/crates/embedded-hal
-[Portability]: ../portability/portability.md
+[Portability]: ../portability/index.md
 [F3]: https://crates.io/crates/f3
 
 
@@ -40,7 +40,7 @@ fn main() {
 
 The functions on the `SYST` struct map pretty closely to the functionality defined by the ARM Technical Reference Manual for this peripheral. There's nothing in this API about 'delaying for X milliseconds' - we have to crudely implement that ourselves using a `while` loop. Note that we can't access our `SYST` struct until we have called `Peripherals::take()` - this is a special routine that guarantees that there is only one `SYST` structure in our entire program. For more on that, see the [Peripherals] section.
 
-[Peripherals]: ../peripherals/peripherals.md
+[Peripherals]: ../peripherals/index.md
 
 ## Using a Peripheral Access Crate (PAC)
 
@@ -179,7 +179,7 @@ fn main() -> ! {
     );
 
     loop {
-        writeln!(uart, "Hello, World!\r\n").unwrap();   
+        writeln!(uart, "Hello, World!\r\n").unwrap();
     }
 }
 ```