These server_cfg.txt is just a text backup I do believe. Its there for the purpose of showing you how to format one I think, although it appears to be formatted incorrectly.
Server.cfg is all the stuff for the server like defaultgamemode, cheats, rate settings, sv_lan, ect.
autoexec.cfg will also run commands and other scripts at start up.
example:
exec server.cfg
exec testscript.cfg
exec serverlocked.cfg