doc: improvements for the chip operations
doc: improvements for the chip operations

Tweak the docs for the low-level chip API a bit.

Signed-off-by: Bartosz Golaszewski <108de5fbc428215dc26df4468b48691526611148@gmail.com>

brgl/libgpiod,brgl/libgpiod,brgl/libgpiod,brgl/libgpiod