docs: add contributing section

[fry69]

This is an attempt on creating a contributing section in the Fresh documentation.

Most of this was generated by Claude Clode. It is certainly too verbose in some places and may contain incorrect or misleading hints and statements.

But it is a start and some parts of this seem salvageable.

Happy to hear comments if I should work on this a bit more, or if there are other plans for a contributing section.

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This was written by Claude Code:

Summary of Changes

1. Updated docs/toc.ts

• Added a new "Contributing" section to the latest documentation
• Included pages for "Local Development" and "Testing Changes"

2. Created Documentation Files

docs/latest/contributing/index.md

• Overview of contribution guidelines
• Repository structure explanation
• Basic workflow steps
• Links to resources and community

docs/latest/contributing/local-development.md

• Two development scenarios: Working on Fresh itself vs. testing in external projects
• Workspace configuration: How packages automatically link within the repo
• External project testing: Using links in deno.json to override JSR packages
• Practical examples: Complete setup with code samples
• Common development tasks: Debugging, package dependencies, performance tips
• Troubleshooting: Common issues and solutions

docs/latest/contributing/testing.md

• Required checks: deno task ok before submitting PRs
• Test suite overview: Patterns, execution, permissions
• Multiple testing approaches: Unit tests, documentation site, Vite plugin demo
• Feature-specific workflows: Different testing strategies for different types of changes
• Best practices: Writing good tests, snapshot testing, manual verification
• Debugging: Common issues and debugging techniques

3. Updated CLAUDE.md

• Added a concise Contributing section that references the full documentation
• Maintained high-level, maintainable information
• Included key commands and concepts for contributors

Key Features

The documentation provides:

• Clear local development setup using Deno's links feature for external testing
• Workspace understanding for internal Fresh development
• Comprehensive testing guidance covering all aspects of contribution testing
• Practical examples with actual configuration snippets
• Troubleshooting help for common development issues
• Maintainable content that won't require frequent updates