Add a hlint rule

[ulidtko]

Hi @vrom911 👋 Long-time fan of Kowainik, here's a first contribution.

I was writing something with Relude, and had a sudden brainfart failing to remember how to say toList 😅
Instead I wrote foldr (:) [] — expecting Relude's HLint ruleset to remind me a less clumsy wording — but alas, it didn't say anything! That I was shocked, says something about the quality of kowainik stuff 😉

Checklist

• I've updated hlint.dhall accordingly to my changes (add new rules for the new imports, remove old ones, when they are outdated, etc.).
• I've generated the new .hlint.yaml file (see this instructions).
• I've updated the CHANGELOG with the short description of my latest changes.
  — 🤔 Prolly not worth it?..