Examine source code of Forge Hammer

{
  "name": "__MSG_appName__",
  "description": "__MSG_appDesc__",
  "default_locale": "en",
  "version": "1.1",
  "manifest_version": 2,
  "permissions": [
    "alarms",
    "storage",
    "tabs",
    "notifications",
    "clipboardWrite",
    "https://*.forgeofempires.com/*"
  ],
  "browser_specific_settings": {
    "gecko": {
      "strict_min_version": "140.0",
      "id": "@forge-hammer",
      "data_collection_permissions": {
        "required": [
          "websiteActivity",
          "websiteContent",
          "personalCommunications",
          "browsingActivity"
        ]
      }
    }
  },
  "browser_action": {
    "default_icon": "images/app16.png",
    "default_popup": "content/info.html",
    "default_title": "__MSG_appName__"
  },
  "icons": {
    "16": "images/app16.png",
    "48": "images/app48.png",
    "128": "images/app128.png"
  },
  "web_accessible_resources": [
    "css/*.css",
    "vendor/*.js",
    "vendor/sounds/*.mp3",
    "js/web/*.*",
    "images/*.*",
    "images/*.*",
    "content/*.html",
    "js/vendor.json",
    "js/internal.json",
    "js/foeproxy.js"
  ],
  "content_scripts": [
    {
      "matches": [
        "https://*.forgeofempires.com/*"
      ],
      "include_globs": [
        "*forgeofempires.com/game*"
      ],
      "js": [
        "js/foeproxy.js"
      ],
      "run_at": "document_start",
      "world": "MAIN"
    },
    {
      "matches": [
        "https://*.forgeofempires.com/*"
      ],
      "include_globs": [
        "*forgeofempires.com/game*"
      ],
      "js": [
        "js/foeproxy-fallback.js"
      ],
      "run_at": "document_start"
    },
    {
      "matches": [
        "https://*.forgeofempires.com/*"
      ],
      "include_globs": [
        "*forgeofempires.com/game*"
      ],
      "js": [
        "vendor/browser-polyfill/browser-polyfill.min.js",
        "js/web/_languages/js/_languages.js",
        "js/inject.js"
      ],
      "run_at": "document_end"
    }
  ],
  "background": {
    "scripts": [
      "vendor/browser-polyfill/browser-polyfill.min.js",
      "vendor/dexie/dexie.min.js",
      "background.js"
    ],
    "persistent": true
  }
}