Examine source code of Copy text of element

{
  "manifest_version": 2,
  "name": "__MSG_extensionName__",
  "description": "__MSG_extensionDescription__",
  "version": "1.9",
  "default_locale": "en",
  "browser_specific_settings": {
    "gecko": {
      "id": "copy_elements_text@utb.dip.jp",
      "strict_min_version": "81.0"
    }
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "icons": {
    "16": "icon.svg",
    "48": "icon.svg",
    "96": "icon.svg"
  },
  "options_ui": {
    "page": "options.html"
  },
  "permissions": [
    "menus",
    "activeTab",
    "clipboardWrite",
    "notifications",
    "storage"
  ]
}