Split up documentation

[eifinger]

Closes: #558

[Copilot]

Pull Request Overview

This PR splits up the documentation by extracting detailed configuration sections from the main README.md into separate dedicated documentation files. This improves maintainability and makes the README more focused on basic usage while providing comprehensive advanced configuration in organized documents.

• Split comprehensive documentation into focused files for different configuration areas
• Streamlined the main README to focus on basic usage with links to advanced documentation
• Reorganized content structure to improve discoverability and maintenance

Reviewed Changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
docs/environment-and-tools.md	New file covering environment activation, tool directory configuration, authentication, and environment variables
docs/customization.md	New file for advanced customization including checksum validation, custom manifests, and problem matchers
docs/caching.md	New file with comprehensive caching configuration documentation
docs/advanced-version-configuration.md	New file covering version resolution strategies and configuration file options
README.md	Streamlined to focus on basic usage with consolidated inputs/outputs section and links to detailed documentation

Comments suppressed due to low confidence (1)

README.md:1

• Corrected path reference from 'uv-tool-dir' to 'setup-uv-cache' for consistency with the preceding context.

# setup-uv