If your server is gophernicus, and gophernicus is the standard
server for gopher in the sdf, you're in luck, and, in a bit of a
trap, for gophernicus makes gophermaps easier, but it's a bit
peculiar at that, having its own set of holy rules.  Follow them
and be happy!

Just in case: a gophermap is an index file that links to other
resources (usually files or directories aka folders)

In gophernicus you want to name your gophermaps, gophermap or
whatever.gophermap.  Alternatively, if you don't keep a
gophermap in a folder, gophernicus will kindly generate one
for you.  In that case, please, keep an "about.txt" in each
folder, telling us what it contains, etc and/or have meaningful
file names.  Much appreciated.  Think in your poor readers!
Love.

The TLDR is

a) Lines that do NOT contain any tabs are treated a plain text 
b) A line staring with an exclamation mark is a title 
c) Lines that contain any tabs are links

Regarding links.  This is how you do them

0A text file<..TAB..>text_file.txt
0A text file insider a directory called folder<..TAB..>folder/other_text_file.txt
1A directory called "folder"<..TAB..>folder

Note the 0 and 1 before the link line. 0 indicates "plain text",
1 to directories, I is for images

That should be enough to get your phlog going.
To know how to link to other gophersites, web sites, etc,
check the docs.

https://github.com/gophernicus/gophernicus/blob/master/README.gophermap

You can do anything if you read the docs.