Examine source code of wtfrule

{
  "manifest_version": 3,
  "name": "wtfrule",
  "version": "1.0",
  "description": "Adds a tooltip to quickly look up rules on ChiefDelphi",
  "icons": {
    "48": "icons/48.png",
    "96": "icons/96.png"
  },
  "background": {
    "scripts": [
      "wtfrule.js"
    ]
  },
  "permissions": [
    "webRequest",
    "webRequestBlocking",
    "webRequestFilterResponse"
  ],
  "host_permissions": [
    "*://*.chiefdelphi.com/*"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "wtfrule@fake.is-a.dev"
    }
  }
}