Examine source code of Open Translate Addon

{
  "manifest_version": 2,
  "name": "Unofficial LibreTranslate API",
  "version": "0.2.1",
  "description": "in place translation to aid language learners with unfamiliar vocabulary",
  "icons": {
    "1048": "icons/libtrans_icon_1048_adjusted.png"
  },
  "content_scripts": [
    {
      "all_frames": true,
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "common.js",
        "content.js"
      ]
    }
  ],
  "permissions": [
    "storage",
    "webRequest",
    "https://translate.terraprint.co/*",
    "http://localhost/*",
    "https://libretranslate.com/*",
    "https://libretranslate.de/*",
    "https://translate.argosopentech.com/*",
    "https://trans.zillyhuhn.com/*",
    "https://libretranslate.esmailebob.xyz/*",
    "https://libretranslate.pussthecat.org/*"
  ],
  "background": {
    "scripts": [
      "common.js",
      "background.js"
    ]
  },
  "browser_action": {
    "default_title": "Unofficial LibreTranslate API",
    "default_popup": "popup.html",
    "default_icon": {
      "1048": "icons/libtrans_icon_1048_adjusted.png"
    }
  },
  "options_ui": {
    "page": "options.html",
    "browser_style": true,
    "chrome_style": true
  },
  "broswer_specific_settings": {
    "gecko": {
      "id": "voca@terraprint.co",
      "strict_min_version": "57.0"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{81a3e2b2-02c2-4473-a71d-72e0ea3aec60}"
    }
  }
}