Add Spanish Translated README Template (BLANK_README_ES.md)

[GrunCrow]

This pull request adds a new file named BLANK_README_ES.md, which is the Spanish translation of the original README template. The translated file follows the same structure and sections as the original, but all content has been translated into Spanish to better support Spanish-speaking contributors.

Changes Made:

• Added BLANK_README_ES.md with translated content.
• Updated section titles and instructions in Spanish.
• Maintained the same structure and placeholders as the original README.

[actuarysailor]

This should be done following standard conventions, such as those outlined here.