Examine source code of Red Border Highlighter

{
  "manifest_version": 2,
  "name": "Red Border Highlighter",
  "version": "1.0",
  "description": "Highlight selected text with a red border",
  "permissions": [
    "activeTab"
  ],
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ]
    }
  ],
  "browser_action": {
    "default_icon": {
      "16": "icons/icon16.png",
      "48": "icons/icon48.png",
      "128": "icons/icon128.png"
    },
    "default_popup": "popup.html"
  },
  "icons": {
    "16": "icons/icon16.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{3be4e9d0-e378-4c60-83b6-198588380cac}"
    }
  }
}