Examine source code of Fast Dark

{
  "icons": {
    "16": "icon16.plasmo.e7bcd3ac.png",
    "32": "icon32.plasmo.ce39377b.png",
    "48": "icon48.plasmo.3c17e113.png",
    "64": "icon64.plasmo.df317abe.png",
    "128": "icon128.plasmo.6a4310c5.png"
  },
  "manifest_version": 2,
  "browser_action": {
    "default_icon": {
      "16": "icon16.plasmo.e7bcd3ac.png",
      "32": "icon32.plasmo.ce39377b.png",
      "48": "icon48.plasmo.3c17e113.png",
      "64": "icon64.plasmo.df317abe.png",
      "128": "icon128.plasmo.6a4310c5.png"
    },
    "default_popup": "popup.html"
  },
  "version": "0.0.1",
  "author": "roci",
  "name": "Fast dark",
  "description": "Make fast.com dark.",
  "permissions": [
    "https://fast.com/*"
  ],
  "content_scripts": [
    {
      "matches": [
        "https://fast.com/*"
      ],
      "js": [
        "content.0286da44.js"
      ],
      "run_at": "document_start",
      "all_frames": true,
      "css": []
    }
  ],
  "web_accessible_resources": [
    "content.90bfaa76.css"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{b50577a8-b379-4571-89da-3941dbc753a8}"
    }
  }
}