feat: update extension packages docs

[TimoGlastra]

Simplify structure, update to work with new versions of packages, and move some docs over from the readme of the packages

[berendsliedrecht]

Seems like it is near identical to the README. I think it is fine to have it like the as you will have one place for all the docs, but keeping it in sync might become a bit annoying. Would be nice if we can have urls for the markdown we would like to render.

[TimoGlastra]

Seems like it is near identical to the README. I think it is fine to have it like the as you will have one place for all the docs, but keeping it in sync might become a bit annoying. Would be nice if we can have urls for the markdown we would like to render.

Yes, my idea was to remove it from the README and always point to the docs. that way it's in one place and the README is really simple