Examine source code of Enhanced SteamGifts & SteamTrades (ESGST)

{
  "manifest_version": 2,
  "name": "Enhanced SteamGifts & SteamTrades (ESGST)",
  "version": "8.9.4",
  "description": "A script that adds some cool features to SteamGifts and SteamTrades.",
  "icons": {
    "64": "icon.png"
  },
  "author": "rafaelgomesxyz",
  "background": {
    "scripts": [
      "lib/browser-polyfill.js",
      "eventPage.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.steamgifts.com/*",
        "*://*.steamtrades.com/*"
      ],
      "js": [
        "lib/browser-polyfill.js",
        "esgst.js"
      ],
      "run_at": "document_start"
    }
  ],
  "permissions": [
    "storage",
    "unlimitedStorage",
    "*://*.steamgifts.com/*",
    "*://*.steamtrades.com/*"
  ],
  "optional_permissions": [
    "cookies",
    "webRequest",
    "webRequestBlocking",
    "<all_urls>",
    "*://*.api.dropboxapi.com/*",
    "*://*.api.imgur.com/*",
    "*://*.api.steampowered.com/*",
    "*://*.content.dropboxapi.com/*",
    "*://*.files.1drv.com/*",
    "*://*.github.com/*",
    "*://*.googleapis.com/*",
    "*://*.graph.microsoft.com/*",
    "*://*.isthereanydeal.com/*",
    "*://*.esgst.rafaelgomes.xyz/*",
    "*://*.raw.githubusercontent.com/*",
    "*://*.script.google.com/*",
    "*://*.script.googleusercontent.com/*",
    "*://*.steam-tracker.com/*",
    "*://*.steamcommunity.com/*",
    "*://*.store.steampowered.com/*",
    "*://*.userstyles.org/*"
  ],
  "short_name": "ESGST",
  "web_accessible_resources": [
    "icon.png",
    "permissions.html"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{71de700c-ca62-4e31-9de6-93e3c30633d6}"
    }
  }
}