Simple Letter Counter

manifest.json

{
  "update_url": "https://clients2.google.com/service/update2/crx",
  "action": {
    "default_title": "Simple Letter Counter",
    "default_popup": "counter.html",
    "default_icon": {
      "16": "icons/icon16.png",
      "32": "icons/icon32.png"
    }
  },
  "description": "Add letter and word counter feature to your browser",
  "manifest_version": 3,
  "name": "Simple Letter Counter",
  "icons": {
    "16": "icons/icon16.png",
    "32": "icons/icon32.png",
    "64": "icons/icon64.png",
    "128": "icons/icon128.png"
  },
  "permissions": [
    "contextMenus"
  ],
  "background": {
    "service_worker": "js/background.js"
  },
  "version": "1.0.1"
}