Create side-quest for how video chat apps work

This can be inserted [here](https://github.com/emergentworks/curriculum/tree/main/javascript#side-quest-how-are-applications-like-zoom-or-google-hangout-built). 

The objective of this side-quest is to familiarize mentees with the idea of big data streaming and how they might be able to build their own version of Google Hangout or Zoom.