Examine source code of Gallery Control

{
  "manifest_version": 2,
  "name": "Gallery Control",
  "version": "0.1.8",
  "description": "View next/previous image in a sequence with mouse/touch or keyboard.",
  "icons": {},
  "content_scripts": [
    {
      "matches": [
        "*://*.trekcore.com/gallery/albums/*.jpg",
        "*://*.trekcore.com/gallery/albums/*.JPG",
        "*://*.trekcore.com/gallery/albums/*.jpeg",
        "*://*.trekcore.com/gallery/albums/*.JPEG"
      ],
      "js": [
        "gallery-control.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{2433d435-8d7a-4bec-b02f-82daa6976ce3}",
      "strict_min_version": "48.0"
    },
    "gecko_android": {
      "id": "{2433d435-8d7a-4bec-b02f-82daa6976ce3}",
      "strict_min_version": "113.0"
    }
  }
}