Examine source code of Web Presence

{
  "manifest_version": 2,
  "name": "Web Presence",
  "version": "1.0.0",
  "description": "Updates Discord Rich Presence with your current browser tab information",
  "icons": {
    "16": "icons/icon16.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "content_security_policy": "script-src 'self'; object-src 'self'",
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": {
      "16": "icons/icon16.png",
      "48": "icons/icon48.png",
      "128": "icons/icon128.png"
    }
  },
  "permissions": [
    "storage",
    "tabs",
    "http://localhost:8874/"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "webpresence@example.com",
      "strict_min_version": "79.0"
    }
  }
}