Examine source code of Translate Selection

{
  "manifest_version": 2,
  "name": "Translate Selection",
  "description": "Translate selected text directly above selection",
  "version": "0.4.0",
  "icons": {
    "16": "icon/16.png",
    "32": "icon/32.png",
    "48": "icon/48.png",
    "128": "icon/128.png",
    "256": "icon/256.png"
  },
  "permissions": [
    "storage",
    "https://dictionary.skyeng.ru/*",
    "https://translate.googleapis.com/*",
    "https://vimbox-tts.skyeng.ru/*"
  ],
  "browser_specific_settings": {
    "gecko": {
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      },
      "id": "{80aa068f-b71d-4912-8174-d67eb4af5ba4}"
    }
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_title": "Popup Title",
    "default_popup": "popup.html"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content-scripts/content.js"
      ]
    }
  ],
  "web_accessible_resources": [
    "content-scripts/content.css"
  ]
}