New Section "Retro Chat Clients" Added!

This was suggested by @Alien Hominid since they had a few retro platforms they wanted to share with the community. Plus it'll be fun to talk about the old school chat clients we used to use back in the day even if they're defunct now. I hope you enjoy the new section!

I've renamed this section from "Retro Chat Clients" to "Retro Platforms" since discussions about any retro platform is fine. I know Alien mentioned adding a tag but I think a section is better.