update docs for isp

docs/isp_flashing_guide.md

@@ -64,7 +64,7 @@ Once you've made your changes, you can click the Upload button (right arrow), wh
 
 ## The .hex file
 
-Before flashing your firmware, you're going to need to and do a little preparation. We'll be appending [this bootloader (also a .hex file)](https://github.com/qmk/qmk_firmware/blob/master/util/bootloader.hex) to the end of our firmware by opening the original .hex file in a text editor, and removing the last line, which should be `:00000001FF` (this is an EOF message). After that's been removed, copy the entire bootloader's contents and paste it at the end of the original file, and save it. 
+Before flashing your firmware, you're going to need to and do a little preparation. We'll be appending [this bootloader (also a .hex file)](https://github.com/qmk/qmk_firmware/blob/master/util/bootloader_atmega32u4_1_0_0.hex) to the end of our firmware by opening the original .hex file in a text editor, and removing the last line, which should be `:00000001FF` (this is an EOF message). After that's been removed, copy the entire bootloader's contents and paste it at the end of the original file, and save it. 
 
 It's possible to use other bootloaders here in the same way, but __you need a bootloader__, otherwise you'll have to ISP to write new firmware to your keyboard.
 

docs/memory_write_error,_use_debug_for_more_info.md

@@ -7,7 +7,7 @@ In rare circumstances, your keyboard/device can become unwritable, and `dfu-prog
     [ X  ERROR
     Memory write error, use debug for more info.
 
-Currently the only way to solve this is to [reprogram the chip via ISP](https://www.reddit.com/r/olkb/comments/4rjzen/flashing_error_on_mac_os_x/d52rj8o/). This requires another device to be hooked up to a couple of exposed pins on the PCB. There is a guide on how to do this [here](https://learn.sparkfun.com/tutorials/installing-an-arduino-bootloader), and [this is where things are on the Planck PCB](http://imgur.com/lvbxbHt).
+Currently the only way to solve this is to [reprogram the chip via ISP](https://www.reddit.com/r/olkb/comments/4rjzen/flashing_error_on_mac_os_x/d52rj8o/). This requires another device to be hooked up to a couple of exposed pins on the PCB. __[We now have a guide on ISP flashing](isp_flashing_guide.md)__ and [this is where things are on the Planck PCB](http://imgur.com/lvbxbHt).
 
 An example command to flash the board once things are hooked up is: