Idea: New-project-starter repo templates

I'm not sure if this is the best place to record this idea; it also probably relates to haskell.org ( / a general unification ); but I just wanted to note it down.

Given GitHub's ["template" repos](https://docs.github.com/en/repositories/creating-and-managing-repositories/creating-a-template-repository), I thought it might be nice to create a couple for people looking to get started with Haskell in a variety of ways.

Immediate ideas I have are:

- A simple project with stack/hpack,
- A simple project with cabal,
- Some combination of the above with CI,
- Some combination of the above with tests/quickcheck/hedgehog
- A simple project with nix-flakes in some manner ([stacklock2nix](https://github.com/cdepillabout/stacklock2nix), ???)
- Could also include the HF recommended guidelines for code of conduct, communication, etc.

Does anyone else have other thoughts? Could be a nice simple thing to maintain and point new people to; as long as it doesn't become a maintenance burden (i.e. it's community-maintained.)

This could probably feed into related ideas around the ['create-haskell-app' idea from the Discourse discussion](https://discourse.haskell.org/t/convenience-in-the-haskell-ecosystem/7731/36), but I don't think they should necessarily be coupled, as it's possible to do either independently, and later merge as appropriate.

Start by reviewing GitHub's template-repository guidance and the linked create-haskell-app discussion. Compare the proposed stack/hpack, cabal, CI, testing, and nix-flakes options, then define a focused set of community-maintained templates and guidelines; done means the chosen scope and maintenance approach are agreed.

Vom Indexierungsmodell aus dem Issue-Text verfasst.