Examine source code of CF-Daily

{
  "manifest_version": 2,
  "name": "CF-Daily",
  "version": "1.1.1",
  "description": "Codeforces extension to display a daily question for each user in each rating group",
  "content_scripts": [
    {
      "matches": [
        "https://codeforces.com/problemset*"
      ],
      "css": [
        "src/styles.css"
      ],
      "js": [
        "src/script.js"
      ]
    }
  ],
  "browser_action": {
    "default_icon": {
      "16": "icons/icon16.png",
      "48": "icons/icon48.png",
      "128": "icons/icon128.png"
    },
    "default_popup": "src/popup.html",
    "default_title": "CF-Daily"
  },
  "permissions": [
    "storage"
  ],
  "icons": {
    "16": "icons/icon16.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{08e315a5-a058-4def-bcbf-28cb72c4f98a}"
    }
  }
}