Turn it on
In Settings › Server details switch on the public server page. It is off until you do, and it shows only while the server is on the public list.
What it shows
Name, map, online or offline, players and slots, uptime, last restart, the connect address and a server rating with its parts. Never staff, keys, chat or positions. Search engines are kept out unless you allow them.
Widgets
Copy the embed codes from the page: a status badge and a status widget (free), and with Standard a top-players widget with kills, playtime or longest life, which shows player names only if you tick it.