Examine source code of content-web-blocker

{
  "manifest_version": 2,
  "name": "content-web-blocker",
  "version": "1.1.0",
  "description": "Blocks web pages based on if they contain specified keywords or not",
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "/blocker.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "content-web-blocker@navxe.com"
    }
  },
  "icons": {
    "48": "/icon.png"
  },
  "options_ui": {
    "page": "options.html",
    "browser_style": true
  },
  "permissions": [
    "storage"
  ]
}