Fixed #160 -- Clarified Rust setup requirements.

[vaguul]

Summary

• made the Rust setup requirement more explicit in the root contributing guide
• mirrored the same guidance in the VitePress contributor docs
• called out the Windows MSVC link.exe requirement before contributors run uv sync

Fixed #160.

Validation

• git diff --check
• npm run docs:reference:check
• npm run docs:build (fails on existing VitePress dead links in generated reference docs; this change does not touch those links)

AI-assisted drafting was used; I reviewed the final docs diff and ran the checks above.

[greptile-apps]

Greptile Summary

This PR clarifies the local setup requirements for contributors.

• Adds a native linker requirement to the Rust prerequisite.
• Explains that the Rust router extension is built through maturin during setup.
• Calls out the Windows Visual Studio Build Tools requirement for link.exe.
• Mirrors the guidance in the VitePress contributor docs.

Confidence Score: 5/5

Safe to merge; this is a documentation-only change clarifying contributor setup prerequisites.

The touched files only update setup guidance and do not alter runtime code, build logic, or generated API behavior.

T-Rex Logs

What T-Rex did

• Inspected the pre-change Rust root contributing setup and captured the base state, including the command, working directory, and exit code.
• Inspected the post-change Rust root contributing setup and captured the updated head state, including the command, working directory, and exit code, with the Local Setup excerpt updated to include contract terms.
• Viewed the pre-change VitePress contributor docs capture and confirmed the base Requirements list contained Rust stable with no maturin, Windows, or linker specifics.
• Viewed the post-change VitePress contributor docs capture and confirmed Rust stable with native linker and explained changes for maturin, uv, Python-only updates, Visual Studio Build Tools, and link.exe.

_{Ran code and verified through T-Rex}

_{Reviews (1): Last reviewed commit: "Fixed #160 -- Clarified Rust setup requi..." | Re-trigger Greptile}

[DevilsAutumn]

Looks good, Thankyou @vaguul !