Upgrade to latest versions of jQuery and lightgallery

[oliworx]

should not be a big deal,
as I already did it in this cloned theme: https://github.com/oliworx/theme-classic

[rprieto]

Hi, this is a good idea. It would solve issues like thumbsup/thumbsup#248.

Unfortunately LightGallery switched to a GPL license after version 1.2. As far as I understand, newer versions cannot be included in Thumbsup anymore (which is MIT licensed). I raised this in sachinchoolur/lightGallery#256 but we couldn't find a solution.

I'm open to any ideas on how to integrate with a GPL solution. For example, the themes could switch to GPL, and be downloaded dynamically instead of being bundled, such as --theme @thumbsup/classic. However it would require an internet connexion, which is not needed today.