Examine source code of Textcase Converter

{
  "manifest_version": 2,
  "name": "__MSG_extensionName__",
  "description": "__MSG_extensionDescription__",
  "version": "1.0",
  "default_locale": "en",
  "icons": {
    "48": "icons/border-48.png"
  },
  "background": {
    "scripts": [
      "textcase.js"
    ]
  },
  "permissions": [
    "contextMenus",
    "<all_urls>"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{c2ff586a-7f27-47a2-b374-eda5d96e676e}"
    }
  }
}