Preamble - What is hackage

file to edit: https://github.com/haskell/cabal-userguide/blob/main/src/preamble/03_what_is_hackage.md

## Brief Summary

Hackage is a key piece of haskell infrastructure. It is also critical to cabal, and (in my opinion) receives very little treatment in documentation in comparison to how critical it is. This chapter should go over key hackage features and why they are important for someone who wants to use Cabal.

## Resources

[Hackage Website](https://hackage.haskell.org/)
[How Cabal uses hackage](https://cabal.readthedocs.io/en/3.4/intro.html)