Examine source code of Zero: Word Replacer

{
  "manifest_version": 2,
  "name": "Zero: Word Replacer",
  "version": "1.3",
  "browser_specific_settings": {
    "gecko": {
      "id": "zerowordreplacer@memebigboy.com"
    }
  },
  "decription": "Replaces words and stuff",
  "icons": {
    "48": "icons/zero48.png",
    "96": "icons/zero96.png"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "javascript/content_script.js"
      ],
      "all_frames": true,
      "run_at": "document_start"
    }
  ],
  "browser_action": {
    "default_icon": "icons/zero48.png",
    "default_title": "zero",
    "default_popup": "html/popup.html"
  },
  "permissions": [
    "storage",
    "<all_urls>"
  ]
}