Examine source code of Kanban WIP for Trello

{
  "manifest_version": 2,
  "name": "Kanban WIP for Trello",
  "version": "1.0.4resigned1",
  "description": "Adds work-in-progress limits to Trello lists supporting a Kanban workflow.",
  "icons": {
    "128": "icon.png"
  },
  "author": "Nathan Harkenrider",
  "content_scripts": [
    {
      "matches": [
        "https://trello.com/*"
      ],
      "css": [
        "extension.css"
      ],
      "js": [
        "extension.js"
      ]
    }
  ],
  "homepage_url": "https://github.com/NateHark/TrelloWIPLimits",
  "browser_specific_settings": {
    "gecko": {
      "id": "{c8700647-95e5-4c44-b30a-ace15d9f1321}"
    }
  }
}