Add Square 20 Regular icon

<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 20 20" width="24" height="24"><path fill="currentColor" d="M6 3a3 3 0 0 0-3 3v8a3 3 0 0 0 3 3h8a3 3 0 0 0 3-3V6a3 3 0 0 0-3-3H6ZM4 6a2 2 0 0 1 2-2h8a2 2 0 0 1 2 2v8a2 2 0 0 1-2 2H6a2 2 0 0 1-2-2V6Zm6.5.5a.5.5 0 0 0-1 0v3h-3a.5.5 0 0 0 0 1h3v3a.5.5 0 1 0 1 0v-3h3a.5.5 0 1 0 0-1h-3v-3Z"/></svg>