This guide is meant for distribution/OS packagers to give some hints and ideas for making Geany-Themes available to end-users.
The Geany-Themes files are just .conf files that get put into a
directory where Geany is looking for them. Assuming prefix $PREFIX,
which is where Geany is itself installed, the files should be installed
to $PREFIX/share/geany/colorschemes. Inside the repository, the
colorschemes are inside the colorschemes directory.
For example, a common installation location in Linux would be:
/usr/share/geany/colorschemes
Or if you're packaging for Windows, the directory will likely be something like this (I didn't boot Windows to verify):
C:\Program Files\Geany\shared\geany\colorschemes
You'll probably also want/need to add some other files as described
below, but since the attributions/copyrights/credits are inside each
their own .conf file, you could safely just ship the .conf files.
Many of the colour schemes have different license. The canonical
reference to the licenses used is found at the beginning of each
.conf file in the colorschemes directory. All of the licenses are
free-software friendly but it is up to you to determine if the licenses
are compatible with your distribution method/rules. Feel free to drop
any colour schemes that do not suit your packaging/licensing needs by
just excluding that particular scheme. The default/recommended license
is GPL v2.
I created a GNU Make file that has most of the stuff needed to create a package. You can run it like this:
$ make dist
You can use this created archive as the template for your package. It contains all of the files you should distribute and none of the meta stuff you don't need. See the Makefile itself for more ideas.
Since you know more than me about your distribution's requirements, I'll not go into any more detail than this.