Examine source code of Rotate Image

{
  "name": "Rotate Image",
  "version": "2.0.0",
  "description": "Context Menu: Rotate an image on a web page in +/- 90 degrees steps",
  "manifest_version": 3,
  "background": {
    "scripts": [
      "backgroundScript.js"
    ],
    "type": "module"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "contentScript.js"
      ]
    }
  ],
  "permissions": [
    "activeTab",
    "contextMenus"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{bd490218-d863-45c9-8ffa-490ba0a91577}"
    }
  }
}