Examine source code of d3coder Plus

{
  "manifest_version": 2,
  "name": "d3coder",
  "version": "5.1.1",
  "description": "Encoding/Decoding Plugin for various types of encoding like base64, rot13 or unix timestamp conversion",
  "options_ui": {
    "page": "html/menu_ui.html",
    "open_in_tab": false
  },
  "permissions": [
    "contextMenus",
    "clipboardWrite",
    "storage",
    "scripting",
    "activeTab"
  ],
  "background": {
    "scripts": [
      "js/serviceworker.js"
    ],
    "persistent": false
  },
  "icons": {
    "16": "images/icon16.png",
    "48": "images/icon48.png",
    "128": "images/icon128.png"
  },
  "default_locale": "en",
  "web_accessible_resources": [
    "images/icon16.png",
    "images/icon48.png",
    "images/icon128.png"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{a6c7d03e-7eba-455e-86f1-21bf0fdca777}"
    }
  }
}