Examine source code of dfeed

{
  "manifest_version": 2,
  "name": "dfeed",
  "description": "Add feeds to dfeed.",
  "version": "0.1",
  "permissions": [
    "activeTab",
    "contextMenus",
    "https://dfeed.net/"
  ],
  "icons": {
    "512": "icon.png"
  },
  "browser_action": {
    "default_icon": "icon.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  }
}