Examine source code of Copy Text Content

{
  "name": "Copy Text Content",
  "browser_specific_settings": {
    "gecko": {
      "id": "copyText@mchang.xyz"
    }
  },
  "description": "Copy text content of selected element",
  "version": "0.2",
  "manifest_version": 2,
  "permissions": [
    "menus",
    "clipboardWrite",
    "activeTab",
    "scripting"
  ],
  "icons": {
    "16": "icons/16.png",
    "48": "icons/48.png",
    "128": "icons/128.png"
  },
  "background": {
    "scripts": [
      "src/background.js"
    ]
  }
}