docs(webassembly): replace npm adduser with npm login

[caugner]

Description

Update the Rust to Wasm guide to use npm login instead of npm adduser.

Motivation

npm adduser was removed in npm 12, so readers are told to run a command that no longer exists.

Additional details

npm login has been the documented alias for years, so this is a rename rather than a change in instructions. The link now points at npm-login in the current (v11) CLI docs instead of npm-adduser in the v10 docs.

Related issues and pull requests

Part of mdn/fred#1868.

[github-actions]

Preview URLs (3 pages)

• /en-US/docs/Learn_web_development/Core/Frameworks_libraries/React_getting_started
• /en-US/docs/Learn_web_development/Extensions/Client-side_tools/Package_management
• /en-US/docs/WebAssembly/Guides/Rust_to_Wasm

External URLs (7)

URL: /en-US/docs/Learn_web_development/Core/Frameworks_libraries/React_getting_started
Title: Getting started with React

• https://docs.npmjs.com/cli/configuring-npm/package-json/ (1 time) (Note! This may be a new URL 👀)
• https://docs.npmjs.com/cli/configuring-npm/package-lock-json/ (1 time) (Note! This may be a new URL 👀)

---

URL: /en-US/docs/Learn_web_development/Extensions/Client-side_tools/Package_management
Title: Package management basics

• https://docs.npmjs.com/cli/configuring-npm/package-json/ (1 time) (Note! This may be a new URL 👀)
• https://docs.npmjs.com/cli/using-npm/scripts/ (1 time) (Note! This may be a new URL 👀)

---

URL: /en-US/docs/WebAssembly/Guides/Rust_to_Wasm
Title: Compiling from Rust to WebAssembly

• https://docs.npmjs.com/cli/commands/npm-link/ (1 time) (Note! This may be a new URL 👀)
• https://docs.npmjs.com/cli/commands/npm-login/ (1 time) (Note! This may be a new URL 👀)
• https://www.npmjs.com/ (1 time) (Note! This may be a new URL 👀)

(comment last updated: 2026-09-08 18:16:44)

[Josh-Cena]

Thank you. I switched to versionless URLs because our versioned npm URLs are extremely inconsistent.