Here is example Link:
Crowbar [Source Engine Modding Tool]
steam://url/GroupSteamIDPage/103582791434761767
For give
clickable internet link to player, is another thing.
There are reason(s) why game developers have decide remove this kind feature out. (MOTD page)
- You have already option to spam URL addresses into player view.
Player decide himself, do he want copy/paste that address in his own web browser.
Unless someone have found a way to open web page inside game.