Update Spanish Steward Guidelines to include missing sections

[sidhansu10]

This PR updates the Spanish version of the Steward Guidelines to include sections
that were missing compared to the English version, including Stewardship,
Community Care, Areas, and guidance on becoming a steward.

Fixes #8309

[perminder-17]

Tagging @marioguzzzman for review.

[marioguzzzman]

Thank you for your translation effort @sidhansu10 ! However, this file has already been
translated as part of the 2.0 documentation update in the dev-2.0 branch.

You can see the completed translation here:
https://github.com/processing/p5.js/blob/dev-2.0/contributor_docs/es/steward_guidelines.md

Since this translation already exists and will be included when 2.0 is released,
I'm going to propose @perminder-17 to close this PR to avoid duplicate work.

You can also checkout the translation that has been done and propose better phrasings or flag anything you think would be useful!

¡Gracias por tus contribuciones! 😊