Examine source code of ASL Lookup

{
  "manifest_version": 2,
  "name": "ASL Lookup",
  "version": "1.1",
  "description": "Searches for ASL sign highlighted",
  "icons": {
    "48": "icons/border-48.png"
  },
  "permissions": [
    "contextMenus",
    "activeTab"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "web_accessible_resources": [
    "videos.json"
  ],
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "main.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{0398bb72-65df-4e39-adc1-eae1a872710c}"
    }
  }
}