Examine source code of Text Case Converter

{
  "manifest_version": 2,
  "name": "Text Case Converter",
  "version": "2.0",
  "description": "Converts text to different letter cases including Uppercase, Lowercase, Title Case, Capitalized Case, Sentence Case, and Alternating Case. Features live character/word counts and customizable title case exceptions.",
  "icons": {
    "16": "icons/icon16.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": {
      "16": "icons/icon16.png",
      "48": "icons/icon48.png",
      "128": "icons/icon128.png"
    }
  },
  "permissions": [
    "storage"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{9606e391-e038-43c1-ac83-a158ce341a60}",
      "strict_min_version": "58.0"
    }
  }
}