Translations 091221

Added the Spanish language option to the Translations menu on the top right index page.

steps:

• execute ./install.sh and fix vulnerabilities (npm audit fix --force)
• create the branch
• copy from fr folder to ./es folder
• modify the _navbar.md file for the menu.

Suggestion:
Maybe think about extracting the assets folder to the root to avoid duplicate subfolders? Or leave it but make captures in each language?