Examine source code of darkplane

{
  "name": "darkplane",
  "version": "0.0.2resigned1",
  "manifest_version": 2,
  "description": "A browser extension that changes the look of floatplane.com by changing its CSS",
  "icons": {
    "16": "icons/icon16.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "permissions": [
    "*://www.floatplane.com/*"
  ],
  "content_scripts": [
    {
      "matches": [
        "*://www.floatplane.com/",
        "*://www.floatplane.com/*"
      ],
      "css": [
        "src/inject/css.css"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{eb4dc71b-c83e-4a41-9f99-d703d9d8662e}"
    }
  }
}