doc: somehow wsl2.md was created so the page on https://leanprover.github.io/lean4/doc/make/wsl2.html is empty. This fixes that.
This is the repository for Lean 4, which is currently being released as milestone releases towards a first stable release. Lean 3 is still the latest stable release.
See Setting Up Lean.
Please read our Contribution Guidelines first.
See Building Lean.