ashell: support yaml and toml config

Signed-off-by: Austin Horstman <khaneliman12@gmail.com>

tests/modules/programs/ashell/basic-yaml-config.nix

@@ -0,0 +1,34 @@
+{ pkgs, ... }:
+
+let
+  ashellPackage = pkgs.runCommand "ashell-0.4.1" { } ''
+    mkdir -p $out/bin
+    echo '#!/bin/sh' > $out/bin/ashell
+    chmod +x $out/bin/ashell
+  '';
+in
+{
+  programs.ashell = {
+    enable = true;
+    package = ashellPackage;
+    settings = {
+      modules = {
+        left = [ "Workspaces" ];
+        center = [ "Window Title" ];
+        right = [
+          "SystemInfo"
+          "Clock"
+        ];
+      };
+      workspaces = {
+        visibilityMode = "MonitorSpecific";
+        showEmpty = true;
+      };
+    };
+  };
+
+  nmt.script = ''
+    assertFileExists home-files/.config/ashell.yml
+    assertFileContent home-files/.config/ashell.yml ${./basic-yaml-config-expected.yml}
+  '';
+}