docs(guide): 📝 fix rust-overlay guide

Author: BeiyanYunyi

docs/src/content/docs/00_guides/80_using_a_rust_overlay.md

@@ -52,7 +52,7 @@ In a flake with flake-parts:
               cargo = pkgs.rust-bin.stable.latest.default;
             };
             
-          generatedCargoNix = inputs.crate2nix.tools.${system}.appliedCargoNix {
+          generatedCargoNix = inputs.crate2nix.tools.${system}.generatedCargoNix {
             name = "rustnix";
             src = ./.;
           };