Examine source code of CPH-NG Submit

{
  "manifest_version": 2,
  "name": "__MSG_appName__",
  "description": "__MSG_appDescription__",
  "version": "0.7.8",
  "icons": {
    "16": "icons/16.png",
    "32": "icons/32.png",
    "48": "icons/48.png",
    "128": "icons/128.png"
  },
  "permissions": [
    "activeTab",
    "storage",
    "scripting",
    "notifications",
    "*://atcoder.jp/*",
    "*://codeforces.com/*",
    "*://hydro.ac/*",
    "*://localhost/*",
    "*://m1.codeforces.com/*",
    "*://m2.codeforces.com/*",
    "*://m3.codeforces.com/*",
    "*://vjudge.net/*",
    "*://www.luogu.com.cn/*"
  ],
  "default_locale": "en",
  "web_accessible_resources": [
    "/icons/128.png",
    "/assets/*"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "cph-ng-submit@langningchen.com",
      "strict_min_version": "109.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_title": "CPH-NG Submit",
    "default_popup": "popup.html"
  },
  "content_scripts": [
    {
      "matches": [
        "*://atcoder.jp/*",
        "*://codeforces.com/*",
        "*://hydro.ac/*",
        "*://localhost/*",
        "*://m1.codeforces.com/*",
        "*://m2.codeforces.com/*",
        "*://m3.codeforces.com/*",
        "*://vjudge.net/*",
        "*://www.luogu.com.cn/*"
      ],
      "js": [
        "content-scripts/content.js"
      ]
    }
  ]
}