Update file slides.md

slides/lectures/resources/rust-embedded/slides.md

@@ -136,25 +136,25 @@ const GPIO_OUT_CLR:*mut u32= 0xd000_0018 as *mut u32;
 
 #[panic_handler]
 pub fn panic(_info: &PanicInfo) -> ! {
-    loop { }
+  loop { }
 }
 ```
 
 ```rust {all}{startLine:18}
 #[entry]
 fn main() -> ! {
-    let gpio_ctrl = (GPIOX_CTRL + 8 * pin) as *mut u32;
-    unsafe {
-        write_volatile(gpio_ctrl, 5);
-        write_volatile(GPIO_OE_SET, 1 << pin);
-        let reg = match value {
-        0 => GPIO_OUT_CLR,
-        _ => GPIO_OUT_SET
-        };
-        write_volatile(reg, 1 << pin);
-    };
-
-    loop { }
+  let gpio_ctrl = (GPIOX_CTRL + 8 * pin) as *mut u32;
+  unsafe {
+      write_volatile(gpio_ctrl, 5);
+      write_volatile(GPIO_OE_SET, 1 << pin);
+      let reg = match value {
+      0 => GPIO_OUT_CLR,
+      _ => GPIO_OUT_SET
+      };
+      write_volatile(reg, 1 << pin);
+  };
+
+  loop { }
 }
 ```