feat: get flameshot-once working

configs/flameshot-once.nix

@@ -0,0 +1,37 @@
+{ lib, pkgs, ... }:
+let
+  overrides = self: super: {
+      flameshot-once = self.callPackage <stockholm/krebs/5pkgs/haskell/flameshot-once.nix> {};
+      blessings = self.callPackage <stockholm/krebs/5pkgs/haskell/blessings.nix> {};
+  };
+  flameshot-once = pkgs.callPackage <stockholm/krebs/5pkgs/simple/flameshot-once> {};
+in
+{
+  nixpkgs.overlays = [
+    (import <stockholm/submodules/nix-writers/pkgs>)
+    (import <stockholm/krebs/5pkgs/override>)
+    (self: super: {
+      haskell = super.haskell // {
+        packages = lib.mapAttrs (name: value:
+          if lib.hasAttr "override" value
+            then value.override { inherit overrides; }
+            else value
+        ) super.haskell.packages;
+      };
+      haskellPackages = super.haskellPackages.override {
+        inherit overrides;
+      };
+      xwaitforwindow = super.callPackage <stockholm/krebs/5pkgs/simple/xwaitforwindow.nix> {};
+    })
+  ];
+
+  environment.systemPackages = [
+    (flameshot-once.override {
+      config.imgur.enable = true;
+      config.imgur.createUrl = "http://p.r/image";
+      config.imgur.deleteUrl = "http://p.r/image/delete/%1";
+      config.imgur.xdg-open.browser = "x-www-browser";
+      config.timeout = 200;
+    })
+  ];
+}