docs: add benchmarks around postgres adoption

[Ivansete-status]

Description

Adding benchmark info related to the Postgres adoption.

This is expected to be consumed by https://github.com/waku-org/docs.waku.org/

Notice that all the benchmarks that we will want to make public on https://docs.waku.org should follow this approach.

[gabrielmer]

Woow! Really interesting read! Thanks so much for such a comprehensive investigation! 😍

[NagyZoltanPeter]

As being already familiar with this awesome document but still amazed! Thank a lot for it!

[Ivansete-status]

Thanks for the comments! We are adding all "benchmark" documentation to /docs folder so that this page can be consumed and published by docs.waku.org.

[alrevuelta]

Not sure this repo is the best place for this. Seems more suitable for a blogpost, or research issue.

[Ivansete-status]

Not sure this repo is the best place for this. Seems more suitable for a blogpost, or research issue.

The idea to add the benchmark details in the /docs folder of this repo is to later on consume it and produce documentation on docs.waku.org from Docusaurus.

edited: if you are not completely happy with this location, maybe we can consider moving this to the /docs folder within the research repo. It cannot be an issue, IMO.

( cc @jm-clius @alrevuelta )