docs(contributing): Update setup in contributing/core/developing.md

[bgw]

A lot of stuff here was slightly out-of-date or not as helpful as it could be.

For the Linux bits, I tested with a fresh Ubuntu image in LXD.

[bgw]

• Turbopack: Remove the IntoTraitRef trait, make it an inherent method on Vc #91223
• docs(turbopack): Move singleton pattern documentation from mdbook to rustdoc #91175
• docs(turbopack): Migrate docs about traits from mdbook to rustdocs #91170
• docs(turbopack): Merge task input docs from mdbook into rustdocs #91136
• docs(turbopack): Move mdbook "tasks" docs over to turbo_tasks::function rustdoc #91132
• docs(turbopack): Merge the contents of the "cells" page in the mdbook with our rustdocs #91126
• docs(turbopack): Merge old turbo-tasks concept mdbook page with crate's top-level rustdoc #91120
• docs(turbopack): Copy over turbopack-trace-server docs #91111
• docs(contributing): Update setup in contributing/core/developing.md #91018 👈 (View in Graphite)
• canary

This stack of pull requests is managed by Graphite. Learn more about stacking.