Zeal User Contributions - Not copyright infringement intended
Zeal User Contributions it's not related to Zeal Docs or Kapeli - Dash it just generates XML Files base on Dash public json and Kapeli Comment on Zeal Issue, docsets are described in .xml files and downloaded from Kapeli CDNs.
To install a docset in Zeal: Copy the .xml url, open Zeal, click on Tools -> Docsets... -> Installed
-> Add feed. Paste the URL and click OK
To Add corresponding icons download both icons (icon.png and email@example.com) inside docset folder next to Contents folder and meta.json file.
In Windows by default C:\Users\%username%\AppData\Local\Zeal\Zeal\docsets\<DocsetName>.docset
In Linux by default ~/local/share/zeal/docsets