Examine source code of xPath Finder

{
  "manifest_version": 2,
  "name": "xPath Finder",
  "description": "Click on any element to get the xPath",
  "homepage_url": "https://github.com/trembacz/xpath-finder",
  "version": "1.0.2",
  "icons": {
    "64": "icons/default-64.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_icon": "icons/default-64.png",
    "default_title": "Click on any element to get the xPath"
  },
  "content_scripts": [
    {
      "all_frames": true,
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "inspect.js"
      ]
    }
  ],
  "commands": {
    "toggle-xpath": {
      "suggested_key": {
        "default": "Ctrl+Shift+U",
        "mac": "Command+Shift+U"
      },
      "description": "Toggle plugin"
    }
  },
  "options_ui": {
    "page": "options.html"
  },
  "permissions": [
    "activeTab",
    "<all_urls>",
    "storage"
  ]
}