Examine source code of Open links quietly

{
  "manifest_version": 2,
  "name": "Open link quietly",
  "description": "Open links in muted tabs from the right-click context menu. Also with \"quiet mode\".",
  "version": "1",
  "developer": {
    "name": "martin"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "permissions": [
    "menus",
    "bookmarks"
  ],
  "browser_action": {
    "browser_style": true,
    "default_icon": "tab-audio-playing.svg",
    "default_title": "Open links/tabs quietly",
    "default_area": "tabstrip"
  }
}