jsAPI: add npm install as a custom target command
jsAPI: add npm install as a custom target command

Signed-off-by: Akos Hamori <1f7f87ca6339f7b1c98fa5060270eb45a9e144a7@gmail.com>

MTASZTAKI/ApertusVR,MTASZTAKI/ApertusVR,MTASZTAKI/ApertusVR,MTASZTAKI/ApertusVR,MTASZTAKI/ApertusVR