boards: raspberrypi: rpi_pico2: Add jlink runner for rpi_pico2 board

jlink runner works fine for the Pico2, just like Pico1 (rpi_pico).
Copied relevant lines from rpi_pico/board.cmake.
Fixed typo in documentation.

Signed-off-by: Koen Van Herck <koen.v.herck@gmail.com>