Improve documentation for flashing ST-Link V2 white

[thierer]

I ran into some issues when flashing DirtyJTAG to my ST-Link V2 white clone:

• The pinout of the SWD lines were not documented on the pcb of my adapter.
• The adapter has a stm32 clone which wasn't readily recognized by openocd.
• For some reason flashing didn't work for me with the st-flash tool, but it worked using openocd.

I documented how I solved each of these issues in the hope that it will be useful for others.

Feel free to edit.

[jeanthom]

Hi,

LGTM, thanks a lot for your contribution!