Examine source code of Web Assistant

{
  "manifest_version": 2,
  "name": "Web Assistant",
  "description": "Browser Voice Assistant",
  "version": "0.0.4",
  "icons": {
    "64": "icons/icon-64.png",
    "128": "icons/icon-128.png",
    "256": "icons/icon-256.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{ee706ecf-f943-4c77-8178-f2c97c2f9a59}"
    }
  },
  "background": {
    "scripts": [
      "browser-polyfill.min.js",
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "https://www.google.com/*",
        "https://www.google.com/webhp*",
        "https://www.google.com/search*"
      ],
      "js": [
        "browser-polyfill.min.js",
        "cs_google.js"
      ]
    },
    {
      "matches": [
        "https://www.youtube.com/",
        "https://www.youtube.com/*"
      ],
      "js": [
        "browser-polyfill.min.js",
        "cs_youtube.js"
      ]
    },
    {
      "matches": [
        "https://www.wikipedia.org/",
        "https://*.wikipedia.org/wiki/*"
      ],
      "js": [
        "browser-polyfill.min.js",
        "cs_wikipedia.js"
      ]
    },
    {
      "matches": [
        "https://www.amazon.com/*"
      ],
      "js": [
        "browser-polyfill.min.js",
        "cs_amazon.js"
      ]
    },
    {
      "matches": [
        "<all_urls>"
      ],
      "exclude_matches": [
        "https://www.google.com/*",
        "https://www.google.com/webhp*",
        "https://www.google.com/search*",
        "https://www.youtube.com/",
        "https://www.youtube.com/*",
        "https://www.wikipedia.org/",
        "https://*.wikipedia.org/wiki/*",
        "https://www.amazon.com/*"
      ],
      "js": [
        "browser-polyfill.min.js",
        "cs_all.js"
      ]
    }
  ],
  "browser_action": {
    "default_icon": {
      "64": "icons/icon-64.png"
    },
    "default_title": "Web Assistant",
    "default_popup": "browser-action/index.html"
  },
  "options_ui": {
    "page": "options/index.html"
  },
  "permissions": [
    "<all_urls>"
  ]
}