Examine source code of Submitify

{
  "manifest_version": 2,
  "name": "Submitify",
  "version": "2.0.1",
  "description": "Allows you to submit solutions from the problem page without redirect.",
  "icons": {},
  "content_scripts": [
    {
      "matches": [
        "https://codeforces.com/*",
        "https://codeforces.com/contest/*/problem/*"
      ],
      "js": [
        "Submitify.js"
      ]
    }
  ]
}