Examine source code of LeetCode Daily Badger

{
  "author": "levidos",
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "description": "Extension that opens the LeetCode Daily Challenge page at Firefox start-up. Icon becomes grey once a challenge has been completed that day.",
  "icons": {
    "128": "icons/icon-48-fire.png"
  },
  "browser_action": {
    "default_area": "navbar"
  },
  "manifest_version": 2,
  "name": "LeetCode Daily Badger",
  "permissions": [
    "cookies",
    "*://leetcode.com/*"
  ],
  "host_permissions": [
    "*://*.leetcode.com/*"
  ],
  "version": "0.1.0",
  "browser_specific_settings": {
    "gecko": {
      "id": "{7838cdc4-91a5-4623-ac1c-02d47b21f4fb}"
    }
  }
}