The entity help is a bit outdated. I really need to put out an updated BSP package.
Since TDM was added later, any map that supports DM also supports TDM automatically. I think there is a gamemode value for TDM, though, if you want to make it TDM exclusive (no DM support). I can't remember the number offhand, though.
If you just need to test that your game modes are working, you can use bots ("addbot" at the console, then you can use "botcmd" to make them do things like join teams and such if you need).