Examine source code of Word Circle Dictionary

{
  "manifest_version": 2,
  "name": "Word Circle Dictionary",
  "version": "1.0.8",
  "description": "Provides an English dictionary for each visited web page",
  "icons": {
    "48": "img/icons/icon_48.png",
    "96": "img/icons/icon_96.png"
  },
  "browser_action": {
    "default_icon": {
      "48": "img/icons/icon_48.png"
    },
    "default_title": "Word Circle Dictionary",
    "default_popup": "html/popup.html"
  },
  "background": {
    "scripts": [
      "js/background/background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "css": [
        "css/content.css",
        "css/modal.css",
        "css/definitionbox.css",
        "css/sidebar.css",
        "css/minimodal.css"
      ],
      "js": [
        "js/content/messages.js",
        "js/content/dictionary.js",
        "modal/modal.js",
        "js/content/dom-observer.js",
        "js/content/sidebar.js",
        "js/content/content.js"
      ]
    }
  ],
  "web_accessible_resources": [
    "json/dictionary/*.json",
    "modal/images/*.png",
    "img/icons/*.ico",
    "modal/*.html",
    "html/*.html"
  ],
  "permissions": [
    "<all_urls>",
    "storage",
    "activeTab",
    "tabs",
    "unlimitedStorage"
  ]
}