Examine source code of Selection Highlighter

{
  "manifest_version": 3,
  "name": "Selection Highlighter",
  "version": "3.3.0",
  "description": "Highlight occurrences of selected text, with or without a keypress.",
  "content_scripts": [
    {
      "all_frames": true,
      "run_at": "document_end",
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content_script/main.js"
      ]
    }
  ],
  "action": {
    "default_icon": "images/icon.png",
    "default_title": "Selection Highlighter",
    "default_popup": "popup/index.html"
  },
  "icons": {
    "1024": "images/icon.png"
  },
  "permissions": [
    "storage"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{ee192302-b8b3-450e-a7f8-a3dabdccf2a8}"
    }
  }
}