Examine source code of TF2 Trade Helper

{
  "applications": {
    "gecko": {
      "id": "sebas646@gmail.com",
      "strict_min_version": "57.0"
    }
  },
  "manifest_version": 2,
  "name": "TF2 Trade Helper",
  "short_name": "TF2TH",
  "version": "5",
  "description": "Helps with trading TF2 stuff.",
  "icons": {
    "128": "images/icon128.png"
  },
  "browser_action": {
    "default_icon": "images/icon128.png",
    "default_popup": "popup.html"
  },
  "options_ui": {
    "page": "options.html",
    "open_in_tab": false
  },
  "background": {
    "scripts": [
      "js/background.js"
    ],
    "persistent": false
  },
  "externally_connectable": {
    "matches": [
      "https://backpack.tf/*"
    ]
  },
  "homepage_url": "https://ser646.github.io/",
  "content_scripts": [
    {
      "matches": [
        "*://steamcommunity.com/tradeoffer/*"
      ],
      "js": [
        "js/load.js"
      ],
      "css": [
        "css/script.css"
      ],
      "run_at": "document_end"
    },
    {
      "matches": [
        "*://steamcommunity.com/id/*",
        "*://steamcommunity.com/profiles/*"
      ],
      "js": [
        "js/load2.js"
      ],
      "run_at": "document_end"
    },
    {
      "matches": [
        "*://backpack.tf/classifieds*"
      ],
      "js": [
        "js/BPclassified.js"
      ],
      "css": [
        "css/BPclassified.css"
      ],
      "run_at": "document_end"
    }
  ],
  "permissions": [
    "storage",
    "https://steamcommunity.com/*",
    "cookies"
  ],
  "web_accessible_resources": [
    "js/*",
    "images/*"
  ]
}