Clean up demos README

[aaronchongth]

Feature request

Description

With more fancy gifs and media added onto the README, it is starting to get cluttered and making it difficult to parse information. I would suggest leaving the media and gifs on the main README, with links to more directed information about each demo in docs

[mdfesto]

I take your point. Since RMF Demos is a landing page for lots of collaborators new to RMF (and maybe new to GitHub in some cases), it seems to me like having the info on the README is actually helpful. I'm personally in favor of keeping it "as-is" as you can tell from my recent PR that adds more clutter. 🙈 Hehe, I wrote that PR before seeing this though.