Examine source code of ECS Fix

{
  "applications": {
    "gecko": {
      "id": "ecs-fix@maxgontijo.com.br"
    }
  },
  "manifest_version": 2,
  "name": "ECS Fix",
  "version": "1.0.1",
  "description": "Fix some bugs on ECS tools.",
  "icons": {
    "48": "images/app-icon.png"
  },
  "permissions": [
    "activeTab"
  ],
  "web_accessible_resources": [
    "content/style.css"
  ],
  "content_scripts": [
    {
      "matches": [
        "*://www.ecs.umass.edu/ece/koren/architecture/scoreboard/*"
      ],
      "js": [
        "lib/js/jquery-3.5.1.js",
        "content/ecs-fixer.js"
      ],
      "css": [
        "content/style.css"
      ],
      "all_frames": true
    }
  ]
}