Examine source code of WordSage

{
  "manifest_version": 2,
  "name": "WordSage",
  "version": "1.0",
  "description": "Enhances vocabulary learning by highlighting and explaining advanced words based on user's proficiency level",
  "icons": {
    "48": "icons/icon-48.png",
    "96": "icons/icon-96.png"
  },
  "permissions": [
    "<all_urls>",
    "storage",
    "contextMenus"
  ],
  "browser_action": {
    "default_icon": "icons/icon-48.png",
    "default_title": "WordSage",
    "default_popup": "popup/popup.html"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content_scripts/wordHighlighter.js"
      ],
      "css": [
        "content_scripts/highlightStyles.css"
      ]
    }
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "options_ui": {
    "page": "options/options.html"
  },
  "web_accessible_resources": [
    "data/vocabulary.json"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{ed49d6ea-a78b-49ed-b8d6-d9fb4fd3f376}"
    }
  }
}