fixed some broken links in markdown files

[lirenjie95]

Resolves #7476

Changes:

1. replace https://github.com/processing/p5.js/blob/main/contributor_docs/inline_documentation.md by https://github.com/processing/p5.js/blob/main/contributor_docs/contributing_to_the_p5js_reference.md and change the title to "Inline reference"
2. replace https://p5js.org/learn by https://p5js.org/tutorials

Screenshots of the change:

PR Checklist

• npm run lint passes
• Inline documentation is included / updated
• Unit tests are included / updated

[welcome]

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[limzykenneth]

Looks good. Thanks!