Stretch: Think of ways to allow users to make selections "on-wiki"

[audiodude]

This issue doesn't necessarily concern the operation of WP1 itself. Rather, it's an exploratory issue for us to think about and discuss ways that users could create a selection "on-wiki", similar to the way the "Book builder" selection worked, which was added in #645 and slated for removal in #727.

The most stubborn approach would be a Chrome extension which adds a "Add to my selection" button to Wikipedia interfaces. The user would have to be logged in to both Wikipedia and WP1. We would probably need a special type of Builder that is "hidden" from the interface but which receives additions as prompted by such an extension, and then allows the user to build their ZIM. This would likely require API work in WP1.

A less heavy approach would be to create a User script or Gadget that does something similar. These types of code are specifically designed to be placed directly in the Wikipedia interface and allow the user to take actions. However, it is not clear if either provides ways to do XHR/fetch/AJAX requests to the external WP1 API. This approach would similarly need WP1 API modifications. The advantage is that it leverages existing methods for integrating with the Wikipedia/Mediawiki interface. The disadvantage is that the code would live on-wiki as well, and might need to be duplicated across different language wikis, and could not be properly version controlled.