Examine source code of Translate Selected Text

{
  "name": "__MSG_extName__",
  "description": "__MSG_extDescription__",
  "homepage_url": "https://github.com/rty65tt/firefox-addon-translateselectedtext",
  "short_name": "translateselectedtext",
  "manifest_version": 2,
  "version": "1.0.6",
  "default_locale": "en",
  "permissions": [
    "<all_urls>",
    "clipboardRead",
    "activeTab",
    "storage"
  ],
  "icons": {
    "19": "icons/19.png",
    "32": "icons/32.png",
    "48": "icons/48.png",
    "64": "icons/64.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "translateselectedtext@rty65tt.org",
      "strict_min_version": "80.0"
    }
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "options_ui": {
    "page": "options/index.html"
  },
  "content_scripts": [
    {
      "matches": [
        "http://*/*",
        "https://*/*",
        "<all_urls>"
      ],
      "css": [
        "simple-translate.css"
      ],
      "js": [
        "simple-translate.js"
      ]
    }
  ]
}