Examine source code of AutoJoin for SteamGifts

{
  "background": {
    "persistent": true,
    "scripts": [
      "js/jquery.min.js",
      "js/backgroundpage.js"
    ]
  },
  "content_scripts": [
    {
      "run_at": "document_start",
      "css": [
        "css/general.css"
      ],
      "js": [
        "js/jquery.min.js",
        "js/autoentry.js",
        "js/misc.js",
        "js/settings.js"
      ],
      "matches": [
        "*://www.steamgifts.com/",
        "*://www.steamgifts.com/giveaways/search?*",
        "*://www.steamgifts.com/game/*",
        "*://steamgifts.com/",
        "*://steamgifts.com/giveaways/search?*",
        "*://steamgifts.com/game/*"
      ]
    },
    {
      "js": [
        "js/autojoinSteamQueue.js"
      ],
      "matches": [
        "*://store.steampowered.com/*"
      ]
    },
    {
      "css": [
        "css/general.css"
      ],
      "js": [
        "js/misc.js"
      ],
      "matches": [
        "*://steamgifts.com/giveaways/created/*",
        "*://www.steamgifts.com/giveaways/created/*",
        "*://steamgifts.com/giveaways/entered/*",
        "*://www.steamgifts.com/giveaways/entered/*",
        "*://steamgifts.com/giveaways/won/*",
        "*://www.steamgifts.com/giveaways/won/*",
        "*://steamgifts.com/trades/*",
        "*://www.steamgifts.com/trades/*",
        "*://steamgifts.com/sales/*",
        "*://www.steamgifts.com/sales/*",
        "*://steamgifts.com/discussions/*",
        "*://www.steamgifts.com/discussions/*",
        "*://steamgifts.com/discussion/*",
        "*://www.steamgifts.com/discussion/*",
        "*://steamgifts.com/about/*",
        "*://www.steamgifts.com/about/*",
        "*://steamgifts.com/support/*",
        "*://www.steamgifts.com/support/*",
        "*://steamgifts.com/messages/*",
        "*://www.steamgifts.com/messages/*",
        "*://steamgifts.com/account/*",
        "*://www.steamgifts.com/account/*",
        "*://steamgifts.com/trade/*",
        "*://www.steamgifts.com/trade/*",
        "*://steamgifts.com/users/*",
        "*://www.steamgifts.com/users/*",
        "*://steamgifts.com/user/*",
        "*://www.steamgifts.com/user/*",
        "*://steamgifts.com/giveaway/*",
        "*://www.steamgifts.com/giveaway/*",
        "*://steamgifts.com/legal/*",
        "*://www.steamgifts.com/legal/*"
      ]
    }
  ],
  "icons": {
    "16": "media/autologo16.png",
    "48": "media/autologo48.png",
    "128": "media/autologo.png"
  },
  "applications": {
    "gecko": {
      "id": "jid1-VSlWBGe0y6Q0Iw@jetpack",
      "strict_min_version": "58.0"
    }
  },
  "manifest_version": 2,
  "name": "AutoJoin for SteamGifts",
  "short_name": "AutoJoin",
  "description": "Automatically enters giveaways from Steamgifts.com and site enhancements",
  "permissions": [
    "alarms",
    "notifications",
    "storage",
    "*://www.steamgifts.com/*",
    "*://store.steampowered.com/*"
  ],
  "optional_permissions": [
    "*://steamcommunity.com/profiles/*"
  ],
  "version": "1.9.9",
  "web_accessible_resources": [
    "html/settings.html",
    "css/night.css",
    "media/audio.mp3"
  ],
  "options_ui": {
    "page": "html/settings.html",
    "chrome_style": true
  }
}