Add Laurel user, design, and implementation guides

[keyboardDrummer]

Summary

Restructures and expands the Laurel documentation under docs/verso/:

• Splits the former LaurelDoc into three separate guides: User Guide, Design Guide, and Implementation Guide, each with its own *Main.lean entry point.
• Fills in previously TODO sections and adds coverage for type inference, record types, and frozen vs record types.
• Updates the verso build setup (Makefile, generate.sh, lakefile.toml, index.html) to build the new multi-guide layout.
• Minor cleanups in a few Laurel source files (LaurelAST.lean, Resolution.lean, and others).

Notes

• Based on the noPassDiagnostics branch, so this PR targets that branch. Retarget to main if preferred.
• Changes are documentation-focused; no functional behavior changes intended.