Resolves#8309

Changes:
The PR updates the Spanish steward guidelines to include important sections that were missing from the English version:

• Stewardship (main section)
  • Community Care
  • Areas
  • Becoming a Steward
  • Getting Started with Stewardship

Translation Decisions

I chose to keep the term "Steward" in English accompanied by its contextual Spanish translation "Guías de Área" because there is no direct Spanish translation that fully captures the spirit of the role. Terms like "supervisor" are too hierarchical, while "steward" conveys a sense of care, collaboration, and shared responsibility that is central to p5.js values. The expression "Guías de Área" complements this concept by emphasizing the guiding and educational aspects of the role, as well as maintaining the collaborative and non-hierarchical spirit of the community.

PR Checklist

PR Checklist

• npm run lint passes - (N/A- Documentation-only PR, no code changes)
• [Inline reference] is included / updated - (Updating steward guidelines, not API reference)
• [Unit tests] are included / updated - ( N/A - Documentation update, no code changes)

Note: This is a documentation-only PR updating Spanish translation. No code changes require linting or testing.