GAP 4.8.9 installation with standard packages -- copy to your CoCalc project to get it
## makedoc.g for package XMod, version 29/04/17
## This builds the documentation of the XMod package.
## Needs: GAPDoc package, latex, pdflatex, mkindex
##
LoadPackage( "GAPDoc" );
XModDoc := Filename( DirectoriesPackageLibrary( "XMod", "doc" ), "" );
# use this command if including xymatrix code (added 29/04/17)
SetGapDocLaTeXOptions(rec(EarlyExtraPreamble := "\\usepackage[all]{xy}\n"));
MakeGAPDocDoc( XModDoc, # path to the directory containing the main file
"manual", # the name of the main file (without extension)
# list of (probably source code) files relative
# to path which contain pieces of documentation
# which must be included in the document
[ "../PackageInfo.g" ],
"XMod", # the name of the book used by GAP's online help
"../../..",# optional: relative path to the main GAP root
# directory to produce HTML files with relative
# paths to external books.
# optional: use "MathJax", "Tth" and/or "MathML"
# to produce additional variants of HTML files
"MathJax" # optional: use "MathJax", "Tth" and/or "MathML"
# to produce additional variants of HTML files
);;
# Copy the *.css and *.js files from the styles directory of the GAPDoc
# package into the directory containing the package manual.
CopyHTMLStyleFiles( XModDoc );
SetGapDocLaTeXOptions(GAPDoc2LaTeXProcs.DefaultOptions);
# Create the manual.lab file which is needed if the main manuals or another
# package is referring to your package
GAPDocManualLab( "XMod" );;