Save sideloaded JSON files in data directory #366
Description
I use a lot of keyboards that aren't in the central repo, and are unlikely to be added by their developers. Because of this, I have to sideload their JSON files frequently. I've experimented with adding them to the VIA JSON cache file, but of course that gets overwritten when I refresh the VIA definitions.
Since Vial already has to have a datadir for storing the downloaded VIA definitions, it would be helpful to also use that datadir to store sideloaded files for repeated use.
A minimum viable product would simply be a known path that I can drop JSON files into which is also checked when parsing the existing VIA cache. Since this is not something I would expect non-technical users to use, I don't think it would be absolutely necessary to have any UI import/management support. (For example, GIMP plugins have to be manually installed like this, and it doesn't cause issues with most users of GIMP.)
If you wanted to expose this feature to nontechnical users, a separate "Import" option after the "Sideload" option could be used, or the sideload file picker could just have a checkbox for "keep this JSON in Vial". This would probably also need a small listview dialog for management/deletion of imported definitions, as the target user for the GUI import function would not be likely to manually delete files from the datadir.
Please consider at least the manual-install option, as it would greatly simplify use of Vial for this workflow.