Implement settings dialog and custom menu item management

build/linux/config.json

@@ -0,0 +1,20 @@
+{
+  "favorites": [
+    "/home/brasse",
+    "/home/brasse/test",
+    "/home"
+  ],
+  "text_editor": "msedit",
+  "custom_menu_items": [
+    {
+      "name": "Open in Vs Code",
+      "command": "code $[path]",
+      "applies_to": "Both"
+    },
+    {
+      "name": "Nytt kommando",
+      "command": "echo $[path]",
+      "applies_to": "Both"
+    }
+  ]
+}