docs(GreedyBear): Update for Ruff migration and expand API documentation

[opbot-xd]

Description

Update GreedyBear documentation to reflect Ruff migration (PR #663) and expand API documentation coverage.

Changes

Contribute.md

• Update Code Style section to reflect Ruff migration from black/isort/flake8
• Add detailed Ruff capabilities and rule sets documentation
• Add manual Ruff command examples for contributors

Api-docs.md

• Add missing Cowrie Session API endpoint documentation
• Add comprehensive Serializers section (EnrichmentSerializer, FeedsRequestSerializer, etc.)
• Add Validation Functions section (feed_type_validation, ordering_validation)
• Improve organization with clear section headers
• Fix naming consistency (general_honeypot_list → General Honeypot List)
• Add version note for upcoming FeedsRequestSerializer enhancements

Related PRs

• Migrate from flake8/black/isort to Ruff GreedyBear-Project/GreedyBear#663: Migrate from flake8/black/isort to Ruff (pending merge)

Notes

• Cowrie Session endpoint: Already available in main branch
• Most serializers: Already available in main branch
• FeedsRequestSerializer enhancements: Available from version > 2.4.0 (currently in develop, will auto-update via submodule sync when merged to main)

Checklist

• The pull request is for the branch main
• If I added new documentation related to a new Pull Request that I created, I have added a reference to the related Pull Request
  • If the new documentation will be added in a future release, please add a reference like _Available from version > x.x.x_ where x.x.x is the current version number
• If the additional documentation is a fix, you should directly push to the main branch and do not open this PR.

[opbot-xd]

@mlodic @regulartim

Following our Slack discussion where I asked about documentation workflow and scope:

What was discussed:

• I asked whether to manually update the submodule to develop or just update the markdown files
• Matteo confirmed to just add the new docs to Api-docs.md and let the GitHub Action handle submodule syncing once PRs merge to main
• I asked if I should only document my specific PRs or also add missing components
• Matteo encouraged documenting everything helpful, not just my changes

This PR delivers:

• Ruff migration docs (PR #663) - Code Style section updated with new tooling
• Missing API components docs - Added Cowrie Session endpoint and serializers section
• Version notes for features in develop - Using > 2.4.0 notation as per PR template requirements
• No manual submodule changes - Letting automation handle it as suggested

Thanks for the guidance on the workflow!

[mlodic]

thanks again!