Motivation for this change

shaarli-material is a theme plugin for the shaarli web application.
The version of the theme needs to match shaarli's or else there are server errors, broken scripts and broken styling. shaarli-material is behind by almost a year, so the two versions of shaarli + shaarli-material in the nix store do not work together.
The build process for shaarli-material has changed in 0.10.3 and now depends on npm packages and a gulp script (changelog: https://github.com/kalvn/Shaarli-Material/releases) and I do not know how to update the build recipe for it.
I have not managed to set up a working shaarli + shaarli-material configuration with the prebuilt assets from the GitHub releases page either.

So I'd like to drop the package because it has been unusable for a year, is too difficult to maintain and apparently not used by anyone.

Things done

• Tested using sandboxing (nix.useSandbox on NixOS, or option sandbox in nix.conf on non-NixOS)
• Built on platform(s)
  • NixOS
  • macOS
  • other Linux distributions
• Tested via one or more NixOS test(s) if existing and applicable for the change (look inside nixos/tests)
• Tested compilation of all pkgs that depend on this change using nix-shell -p nix-review --run "nix-review wip"
• Tested execution of all binary files (usually in ./result/bin/)
• Determined the impact on package closure size (by running nix path-info -S before and after)
• Assured whether relevant documentation is up to date
• Fits CONTRIBUTING.md.