#49 addition for manual: create file in config directory

[Anonymous]

I followed the steps in the readme to the letter. It
says ""The configuration files in /patch/of/nagios/etc/
should be writable by the
webserver....". So I did.

But I also gather that nagat also puts a file
(nagatcfg.dat) there, so it also need write access to
that directory (for the web user, apache in my case).

Please add it to the manual, to make it more complete.