Add page descriptions is not really feasible on the prototype server as it requires setting up a wikibase, and linking all the articles to wikibase items with descriptions.

Images can be added by just adding images to the stub articles we created. I done a few for links at the top of the page (e.g Jane Austen).

In T228232#5341138, @Esanders wrote:

Add page descriptions is not really feasible on the prototype server as it requires setting up a wikibase, and linking all the articles to wikibase items with descriptions.

I looked into it and there is actually an easier way to do the second part. I don't want to mess up the test server, but it works for me locally.

First you need to set up Wikibase repo and client, instructions here worked for me: https://www.mediawiki.org/wiki/Wikibase/Installation. Then you set $wgWBClientSettings["allowLocalShortDesc"] = true;.

Now you can set a description by placing {{SHORTDESC:medium test page}} anywhere in the page wikitext. The complicated Wikibase stuff doesn't even have to work (e.g. I haven't figured out how to make it possible to link my local articles to Wikibase items on my wiki…).

This seems to be largely undocumented, but the relevant task describing the feature is T184000.

First you need to set up Wikibase repo and client

Those are big complex extensions that I have found a lot of extra work to keep up to date locally.