Examine source code of Polywork for Twitter

{
  "manifest_version": 2,
  "name": "Polywork",
  "description": "Polywork for Twitter",
  "homepage_url": "https://www.polywork.com/",
  "version": "0.3.0",
  "icons": {
    "16": "icons/icon16.png",
    "48": "icons/icon48.png",
    "64": "icons/icon64.png",
    "96": "icons/icon96.png",
    "128": "icons/icon128.png"
  },
  "content_scripts": [
    {
      "matches": [
        "https://twitter.com/*"
      ],
      "js": [
        "./polywork-twitter.js"
      ]
    }
  ],
  "permissions": [
    "https://www.polywork.com/*"
  ],
  "background": {
    "scripts": [
      "./polywork-background.js"
    ],
    "persistent": false
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{9bbda90d-4483-4de6-9f14-b165492f47b1}"
    }
  }
}