Update src/type-inference.md
Update src/type-inference.md

Co-authored-by: Tshepang Mbambo <e7b73ca0953a5d12982870cd6d45d044b17f68d7@gmail.com>
rust-lang/rustc-dev-guide,rust-lang/rustc-dev-guide,rust-lang/rustc-dev-guide,rust-lang/rustc-dev-guide