Tutorial: Using /video/merge to develop video slideshows

Recently, I showcased the /video/merge Robot by giving an example use case in which video and sound are merged together, aided by the audio_delay parameter. I've now decided to present a more in-depth tutorial, pairing the same Robot together with some of the other powerful Robots available at Transloadit.

This is a companion discussion topic for the original entry at https://transloadit.com/blog/2019/06/slideshow-tutorial/