Fix broken links in contributor_docs/steward_guidelines.md

[aleannab]

Most appropriate sub-area of p5.js?

• Accessibility
• Color
• Core/Environment/Rendering
• Data
• DOM
• Events
• Image
• IO
• Math
• Typography
• Utilities
• WebGL
• Build process
• Unit testing
• Internationalization
• Friendly errors
• Other (specify if possible)

p5.js version

v1.10.0 (latest)

Web browser and version

Firefox v130.0, though would affect all.

Operating system

Windows, though would affect all.

Steps to reproduce this

Steps:

1. Go to: https://github.com/processing/p5.js/blob/main/contributor_docs/steward_guidelines.md
2. Click on respective links (listed in table below).
3. Get a 404 error.

Solutions:

Replace links to the suggested links below.

Here's the updated table with your new entry added:

Source link text:	Current link:	Suggested link:
design principles	https://github.com/processing/p5.js/blob/main/contributor_docs/design_principles.md	https://github.com/processing/p5.js/blob/main/contributor_docs/contributor_guidelines.md#software-design-principles
./tasks/build/eslint-samples.js	https://github.com/processing/p5.js/blob/main/contributor_docs/tasks/build/eslint-samples.js	https://github.com/processing/p5.js/blob/main/tasks/build/eslint-samples.js
./tasks/build/browserify.js	https://github.com/processing/p5.js/blob/main/contributor_docs/tasks/build/browserify.js	https://github.com/processing/p5.js/blob/main/tasks/build/browserify.js
./tasks/test/mocha-chrome.js	https://github.com/processing/p5.js/blob/main/contributor_docs/tasks/test/mocha-chrome.js	https://github.com/processing/p5.js/blob/main/tasks/test/mocha-chrome.js

Let me know if the above works, and I'll submit a PR.