The Cygwin/X web site is stored in sourceware.org git. The repository is git://sourceware.org/git/cygwin-htdocs.git and the path is htdocs/xfree/
A relatively simple way of updating the documentation shown on the web site from the cygwin-x-doc sources is to build the documentation, then install it into a git checkout of the web site, and then check that in, e.g.:
$ cd path-to-website-checkout $ git clone ssh://user@sourceware.org/git/cygwin-htdocs.git $ cd path-to-cygwin-x-doc-checkout $ ./configure --enable-hardcopy --with-docdir=path-to-website-checkout/htdocs/xfree/docs $ make [...] $ make install [...] $ cd path-to-website-checkout/htdocs/xfree/docs $ git add --all $ git commit -m "Rebuild X documentation" |