how to add content from other wordpress plugin fields

I really see tremendous potential with this plugin.

Unfortunately, I can’t figure out how to get the plugin to export data from any additional fields.

1) I have multiple authors on my site, and so I rely on a co-authors plugin to associate one or more authors on any given post. I don’t know how to get these additional authors preserved in the metadata exported to Github.

2) I offer contributors to my site to share their work under one of three Open Content licenses: CC Zero, CC BY, and CC BY-SA. This important licensing information is not exported to Github, because it is content associated with the post from another plugin.

What can I do to get data associated with posts by other plugins, exported over to Github along with the essential wordpress post content?

Here’s an example post from my site: http://opensiddur.org/tanakh/tehilim/psalms-20-by-david-in-ladino-1852/

and here is it exported to Github: https://github.com/aharonium/opensiddur.org/blob/master/_posts/2017-10-05-psalms-20-by-david-in-ladino-1852.md