Update src/implementing_new_feature.md
Update src/implementing_new_feature.md

Co-Authored-By: rajcspsg <0f979e55bdd315d07ba453cd849b326598b0589f@gmail.com>
rust-lang/rustc-dev-guide,rust-lang/rustc-dev-guide,rust-lang/rustc-dev-guide,rust-lang/rustc-dev-guide