docs(GPIO): Updated Kernel driver doc with examples

Updates Linux Kernel GPIO doc with user space examples
and resources. Adjusts formatting.

Signed-off-by: Jonas Wood <[email protected]>

Author: jonaswood01

source/linux/Foundational_Components/Kernel/Kernel_Drivers/GPIO.rst

@@ -162,7 +162,11 @@ Example: Using GPIOs with the *libgpiod* library in user space to toggle a GPIO
       $ gpioset -c 2 23=0
       ^C
 
-   - *Note: '^C' (Ctrl + C) interrupts the command, else the command would not terminate on its own. Use '^C' (Ctrl + C) to stop the command, and the new GPIO value will still remain.*
+   - Note:
+
+      - In Bash, *'^C' (Ctrl + C)* exits the command with *SIGINT*, else the *gpioset* command would not exit on its own. For more info, refer to the *3.7.6 Signals* section in the GNU Bash manual: https://www.gnu.org/software/bash/manual/bash.html.
+
+      - The new GPIO value will remain until an exit signal, like *SIGKILL*, *SIGTERM*, or *SIGINT*; after that, its value is not guaranteed. For more info, reference the *Description* section of the *gpioset* man page: https://libgpiod.readthedocs.io/en/latest/gpioset.html.
 
    - This should have turned the active-high LED "LD11" on the SK-AM62B-P1 on and off.
 
@@ -188,7 +192,7 @@ Example: Using GPIOs with the *libgpiod* library in user space to toggle a GPIO
 
    - For more info on *gpioset*, see its man page: https://libgpiod.readthedocs.io/en/latest/gpioset.html.
 
-For more command-line tools, refer to the *libgpiod* documentation: https://libgpiod.readthedocs.io/en/latest/gpio_tools.html.
+- For more command-line tools, refer to the *libgpiod* documentation: https://libgpiod.readthedocs.io/en/latest/gpio_tools.html.
 
 Example: Using GPIOs on the Raspberry Pi Compatible 40-pin Header on the SK-AM62B-P1 board: