Fix raspi keyboard & hub link (#51)

user/getting-started.md

@@ -6,7 +6,7 @@
 * 2 GiB RAM system memory (4 GiB recommended; before 0.7.0: 4 GiB minimum)
 * VGA capable of 800x600 screen resolution (1024x768 or more recommended)
 * Either a CD/DVD drive or a USB port for booting the installer media
-* On non-Macintosh hardware, a [Raspberry Pi Keyboard and Hub]([https://static.raspberrypi.org/files/product-briefs/210108_Product_Brief_Keyboard_and_Mouse.pdf](https://www.raspberrypi.com/products/raspberry-pi-keyboard-and-hub/)) is recommended as it allows the keyboard and system language to be detected automatically if it is attached while the system is starting up. On Macintosh hardware, the `prev-lang:kbd` EFI variable is usually set and is used to detect the keyboard and system language. Note that the key left to the space bar is used as the Command key (Alt key on PC keyboards, Apple key on Apple keyboards).
+* On non-Macintosh hardware, a [Raspberry Pi Keyboard and Hub](https://www.raspberrypi.com/products/raspberry-pi-keyboard-and-hub/) is recommended as it allows the keyboard and system language to be detected automatically if it is attached while the system is starting up. On Macintosh hardware, the `prev-lang:kbd` EFI variable is usually set and is used to detect the keyboard and system language. Note that the key left to the space bar is used as the Command key (Alt key on PC keyboards, Apple key on Apple keyboards).
 
 Please refer to [FreeBSD Hardware Compatibility](https://www.freebsd.org/doc/en_US.ISO8859-1/books/faq/hardware.html) for more information on individual components.