docs: improve diagnostics user journey (#131)

Expanded the user journey documentation with details on diagnostics, including steps to record before starting an investigation and options for choosing a diagnostic path based on symptoms.

Signed-off-by: JD De Dios Ojeda 89946133+ojedaJD@users.noreply.github.com

nodejs/learn

Source content for the Node.js learning guides, published at https://nodejs.org/learn.

This repository was created as part of nodejs/nodejs.org#8612 to give the Learn content a dedicated home, separate from the main website monorepo. Content editors no longer need to deal with Next.js tooling or website-specific git hooks.

Content

All articles are Markdown files under pages/, grouped by topic:

pages/
├── getting-started/        # Introduction to Node.js
├── asynchronous-work/      # Event loop, callbacks, promises, streams
├── command-line/           # REPL, environment variables, CLI I/O
├── diagnostics/            # Debugging, profiling, memory, performance
├── file-system/            # File paths, stats, reading/writing, folders
├── http/                   # HTTP, fetch, WebSockets, proxies
├── package-management/     # npm, publishing packages, Node-API modules
├── security/               # Security best practices
├── testing/                # Test runner, mocking, code coverage
└── typescript/             # TypeScript with Node.js

The structure is based on Card Sort research conducted at the 2025 Cambridge Node.js Collaborators’ Summit.

Development

npm install
npm run build   # generates static site + Orama search DB in out/

Contributing

See CONTRIBUTING.md.