Spanish translation of Handbook: X11 Chapter (_index.po and _index.adoc)

[alvaradorad_disroot.org]

Summary

Updated the Spanish translation for the X11 chapter of the FreeBSD Handbook. The translation was completed in Weblate and synchronized with the local repository. This patch includes both the source (.po) and the generated AsciiDoc (.adoc) file to ensure the documentation is ready for publication.

Test Plan

1. Verified the .po file using the official FreeBSD toolset.
2. Generated the .adoc file using ./tools/translate.sh.
3. Ran 'make DOC_LANG=es' inside the documentation directory.
4. Confirmed that Hugo builds the site without errors and the X11 chapter renders correctly in Spanish.