Examine source code of Highlight Saver

{
  "manifest_version": 2,
  "name": "Highlight Saver",
  "version": "1.0",
  "description": "Save highlighted text from any website.",
  "permissions": [
    "activeTab",
    "storage"
  ],
  "browser_action": {
    "default_icon": "icon.png",
    "default_popup": "popup.html"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "icons": {
    "48": "icon.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{d26268d7-3645-4a20-a725-682f72f34cd6}"
    }
  }
}