Examine source code of Text to Speech

{
  "manifest_version": 2,
  "name": "Text to Speech",
  "version": "1.0",
  "description": "Speak selected text using a chosen voice.",
  "permissions": [
    "activeTab"
  ],
  "browser_action": {
    "default_icon": {
      "64": "icon64.png",
      "128": "icon128.png"
    },
    "default_popup": "popup.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{0f9339ff-eb98-49d7-9e59-87c7c5f09b73}",
      "strict_min_version": "109.0"
    }
  }
}