Better document internals

[mitar]

I was reading through documentation but could not find more information how things are implemented internally. What I have especially been interested in how is real-time features of records being implanted across multiple database backends. So how it is determined which records have to be updated when something is changed, and how are changes detected in the first place.

See example of a great writeup from Hasura about similar questions. It gives great insight into what were design decisions, how it works, and what are limitations. For Deepstream I cannot really get an understanding of all this.

[yasserf]

Thank you for the suggestion. Will definitely do that at some point!