swh.lister.functionalPackages: add lister getting sources from a JSON file
This lister downloads a JSON file containing a list of sources
provided by the NixOS and Guix distribution. This file looks like:
{
"version": 1
"sources": [
{
"type": "url",
"url": "https://ftpmirror.gnu.org//hello/hello-2.10.tar.gz"
}
],
}
This is a work in progress lister and we need to work on several points:
- [x] define a JSON format
- [] expose the JSON file from a NixOS community managed server (edit(lewo): i'm working on this)