You can place anything you’d like in the footer, really.
Just edit your footer.php file. You can do this by actually opening up the file, which would be located in /wp-content/themes/yourthemefolder/footer.php, and adding in your HTML.
Alternatively, you can go into your Appearance > Editor in your admin area and edit the file, assuming it’s writable on your server.
If that’s what you meant by “accessible.” If you’re referring to accessibility in the “will people with screen readers, disabilities, etc. be able to use this”, that would depend on how well you write your code.
