Examine source code of RMFIX

{
  "manifest_version": 2,
  "name": "RMFIX",
  "version": "1.1",
  "description": "Some fixes for reddit mobile page",
  "content_scripts": [
    {
      "matches": [
        "https://*.reddit.com/*"
      ],
      "js": [
        "package/jquery-3.3.1.min.js",
        "js/rd.js"
      ],
      "all_frames": true
    }
  ]
}