arptables: add Spanish translation

[kant]

• The page(s) are in the correct platform directories: common, linux, osx, windows, sunos, android, etc.
• The page(s) have at most 8 examples.
• The page description(s) have links to documentation or a homepage.
• The page(s) follow the content guidelines.
• The page(s) follow the style guide.
• The PR title conforms to the recommended templates.
• Version of the command being documented (if known):

[tldr-bot]

Hello! I've noticed something unusual when checking this PR:

• The page pages.es/linux/arptables.md has a more info link that does not match the one in the English page. Please check the "More information:" translation as well using https://github.com/tldr-pages/tldr/blob/main/contributing-guides/translation-templates/more-info-link.md.

Is this intended? If so, just ignore this comment. Otherwise, please double-check the commits.