Add preview feature to the exsiting pi-camera-connect js repository

We have an open issue in the https://github.com/launchcodedev/pi-camera-connect for which the maintainer of the repository has explained how to do the implementation (https://github.com/launchcodedev/pi-camera-connect/issues/21). Need to implement this and close the issue. Developers with experience in Node.js and Raspberry pi need to bid.