Examine source code of Key-Drop Extension

{
  "name": "Key-Drop Extension",
  "description": "__MSG_description__",
  "version": "1.0.3",
  "manifest_version": 3,
  "default_locale": "en",
  "browser_specific_settings": {
    "gecko": {
      "id": "extension@key-drop.com",
      "strict_min_version": "42.0"
    }
  },
  "action": {
    "default_popup": "index.html",
    "default_title": "Key-drop",
    "default_icon": {
      "16": "favicon-16x16.png",
      "32": "favicon-32x32.png",
      "48": "favicon-48x48.png",
      "128": "favicon-128x128.png"
    }
  },
  "icons": {
    "16": "favicon-16x16.png",
    "32": "favicon-32x32.png",
    "48": "favicon-48x48.png",
    "128": "favicon-128x128.png"
  },
  "permissions": [
    "cookies"
  ],
  "host_permissions": [
    "<all_urls>"
  ],
  "content_scripts": [
    {
      "matches": [
        "*://*.steamcommunity.com/*"
      ],
      "js": [
        "content-script.js"
      ],
      "css": [
        "content-script.css"
      ]
    }
  ]
}