Examine source code of Save text content to File

{
  "browser_action": {
    "default_icon": {
      "19": "assets/icon_16.png",
      "38": "assets/icon_128.png"
    }
  },
  "name": "Save text to File",
  "short_name": "Save text of web page to file",
  "icons": {
    "16": "assets/icon_16.png",
    "128": "assets/icon_128.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "applications": {
    "gecko": {
      "id": "jid1-0AMem58mOvHnww@jetpack",
      "strict_min_version": "57.0"
    }
  },
  "version": "1.3.1",
  "manifest_version": 2,
  "permissions": [
    "tabs",
    "<all_urls>",
    "contextMenus"
  ],
  "description": "A useful addon to save quickly text content of web page "
}