Examine source code of Open Links in Background

{
  "manifest_version": 2,
  "name": "Auto Open Links in Background",
  "version": "2.1",
  "description": "Automatically opens clicked links in background tabs",
  "permissions": [
    "tabs"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "icons": {
    "48": "icon.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{41e1ec48-2508-4d4b-935f-075baa7d0333}",
      "strict_min_version": "58.0"
    }
  }
}