Manual install adjust link path

[FelixOstermeier]

For the manual install of klipper LED effects the instructions state to link the file to the klipper directory via
ln -s klipper-led_effect/led_effect.py ~/klipper/extras/led_effect.py
but I think the correct default path for linking should be
ln -s klipper-led_effect/led_effect.py ~/klipper/klippy/extras/led_effect.py

Edit:
Same goes for the manual uninstall by removing the link. The link tries to remove ~/klipper/extras/led_effect.py but the install script links to ~/klipper/klippy/extras/led_effect.py