General unification and improvement

[vladdez]

Current Todos:

• Add correct citations for each package to the UnfoldDocs landing page.
  • requires creating Zenodo links for each of them
• @vladdez , @ReneSkukies , could you review the contribution, development, and installation sections and create PRs or open issues/discussions for any improvements you'd like to see? If everything is perfect already, that's fine too. ;)
• @vladdez , you wanted to contribute a "code-style" document. Could you review the current documents and provide a first draft with a similar level of complexity?
• Replace the links to individual documents with links to the UnfoldDocs website.
• I’d like to more prominently display the names of people responsible for individual packages. What do you think? Maybe on the landing page?
• Unify landing pages to match the style of UnfoldSim and UnfoldMixedModels.
• Finally manage to generate stable, dev, and versioned versions of all docs. ;)
• Register UnfoldStats.jl and UnfoldDecode.jl.
• Fix the logos for each package in the top left corner and add dark/light mode versions (already on the cloud and added to UnfoldDocs.jl).
• Adjust the position of some elements in the header.

written by @behinger with correction of @vladdez