Examine source code of Reddit Search Button

{
  "manifest_version": 2,
  "name": "Reddit Search Button",
  "version": "1.1",
  "description": "Adds a button to search in Reddit only on various search engines",
  "permissions": [
    "activeTab"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{8cb910ee-ca5a-4359-88f2-6ed1c2c3bbd1}",
      "strict_min_version": "58.0"
    }
  },
  "content_scripts": [
    {
      "matches": [
        "https://www.google.com/search*",
        "https://duckduckgo.com/*",
        "https://kagi.com/*",
        "https://www.startpage.com/*",
        "https://search.brave.com/*"
      ],
      "js": [
        "searchEngines.js",
        "content.js"
      ]
    }
  ],
  "icons": {
    "48": "icon.png"
  }
}