Updating setup instructions

[Martinsos]

Hi,
first of all, love the library, I was looking for an option to do GUI in Haskell and while gi-gtk looks pretty good, this just looked much more haskellish and nicer, and I was so happy to see it exists for a couple of years and is still maintained! Thanks for all the effort and time that takes!

I was going through https://github.com/fjvallarino/monomer/blob/main/docs/tutorials/00-setup.md and felt a bit lost / confused, so I wanted to offer some ideas for improving/updating it.
I will list them below, to hear what you think. Then I can do a PR for the changes that make sense.

1. It start with Installation. I was confused, because I expected installation of stuff needed for monomer, like sdl2, but then realized this is about installing Haskell! I would suggest removing this whole section -> if somebody is using monomer, I think it is safe to assume they have Haskell installed and set up.
2. Next comes starter project. On one hand, it is great to have one, as it allows quick start, but on the other hand, there are no other instructions. What I would suggest, is having minimal instructions first: add monomer package, add nanovg flags to cabal.project, add -threaded to ghc-options. Are those minimal options? I am not sure! That is why it would be nice to have them well defined, so I can understand what is minimal/required, and what is optional. Then, you could describe optional but recommended steps, if there are such. And finally, you could then top it off with a starter project that does all that, they just need to clone it.
   The reason why I wanted this was that I didn't want to clone the stack project since I use cabal + I was afraid it might be somewhat old -> instead I wanted to create my own new cabal project with cabal init and then set it up on my own. I ended up going through the starter project and recognizing important parts and carrying them over.
3. These days, I think you can skip recommendations about ghcid. I used it before also, but LSP support is so good in browser these days that I stopped using ghcid. I would at least not keep it in setup, it seems like a bit too much information, and would move it somewhere else in the docs.

Let me know what you think about these changes. If we can agree on something, I can try to make a PR!