Examine source code of TitleCase

{
  "manifest_version": 2,
  "name": "TitleCase",
  "version": "3.1.5resigned1",
  "description": "Transform strings into Title Case, Proper Case, Start Case, Camel Case, Upper Case, and Lower Case. You have 2 ways to change text. Either by right clicking on the field and changing the case or by highlighting and only changing what you highlighted.",
  "homepage_url": "https://www.hightekdesigns.com",
  "applications": {
    "gecko": {
      "id": "TitleCase@htdsoftware.com",
      "strict_min_version": "42.0"
    }
  },
  "icons": {
    "32": "icons/dictionary-32.png",
    "64": "icons/dictionary-64.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "titlecase.js",
        "titlecasechange.js"
      ],
      "run_at": "document_start"
    }
  ],
  "options_ui": {
    "page": "options.html"
  },
  "permissions": [
    "activeTab",
    "tabs",
    "contextMenus",
    "storage",
    "<all_urls>"
  ]
}