Update T480-maximized.md

remove questioned null.bin flash-step correct few typos

Signed-off-by: notgivenby <notgivenby@gmail.com>

Author: notgivenby

Installing-and-Configuring/Flashing-Guides/T480-maximized.md

@@ -15,7 +15,7 @@ Lenovo T480 (Maximized)
 It has never been so easy to access and flash the BIOS chip on a T series machine. It is a straightforward process and takes approximately 10 minutes. 
 
 The ThinkPad T480 has two SPI flash chips important for the port. First chip holds the BIOS, ME, etc. Second holds the Thunderbolt firmware. To access these chips, you only need to remove the back panel.  For whole procedure you will need: a screwdriver, an assembled raspberry pi pico or ch341a SPI programmer 3.3V (3.3V is important!) (e.g. [Modified ch341a SPI programmer](https://novacustom.com/product/modded-ch341a-bios-firmware-programmer-3v/) by Novacustom) and an other laptop/PC with Ubuntu installed. Other linux based OS (in this example Qubes OS, fedora-41-xfce) should be fine too. 
-It is still debated [which programmer should be used and which software (flashprog vs flashrom).
+It is still debated which programmer should be used and which software (flashprog vs flashrom).
 Before you follow the guide make sure you read the [README.md](https://github.com/linuxboot/heads/tree/master/blobs/xx80/README.md) and following information. Some T480 on used marked are affected by an intel bug in the Thunderbolt firmware. In short, the flash chip gets full, so the Thunderbolt fast charging stops working, but slow charging still works. It can affect the usb-c port too. You may want to resolve the problem before flashing Heads using [Lenovo guide ](https://pcsupport.lenovo.com/us/en/products/laptops-and-netbooks/thinkpad-t-series-laptops/thinkpad-t480-type-20l5-20l6/solutions/ht508988-critical-intel-thunderbolt-software-and-firmware-updates-thinkpad) or [libreboot guide](https://libreboot.org/docs/install/t480.html#thunderbolt-issue-read-this-before-flashing).
 Please note, at the moment (Feb 2025) the Thunderbolt data transfer is not supported upstream by coreboot. However, the video output through the Thunderbolt and charging works. So, only the usb-c charging port can be used for the data transfer. Heads provides fixed and padded Thunderbolt firmware for your convenience that will only fix "charging problem" if the bug affected your laptop. The flashing steps are based on libreboot strategy and described in the second part of the guide. Board testers did not have the problem. It is unlikely that you get it if your laptop was in use longer than 12 months before. If you get "charging bug" it is possible to fix with external flashing. However, please note that this neither was tested after Heads installation nor the bug appeared after extensive Heads testing of the board.
 
@@ -125,4 +125,4 @@ Flash the padded Thunderbolt firmware. The firwmare is located in the blobs fold
 ```shell
 sudo flashrom -p ch341a_spi -c YYY -w ~/tb.bin
 ```
-Done.
+Done.