Examine source code of JavaScript Code Injector

{
  "manifest_version": 2,
  "name": "JavaScript Code Injector",
  "version": "0.1",
  "description": "Execute custom JavaScript code for each site",
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": []
    }
  ],
  "background": {
    "scripts": [
      "/src/background.js"
    ]
  },
  "permissions": [
    "<all_urls>",
    "tabs",
    "storage"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "code-injector@yo-wan",
      "strict_min_version": "58.0"
    }
  },
  "options_ui": {
    "page": "/src/options.html",
    "browser_style": true
  },
  "content_security_policy": "script-src 'self'; object-src 'self'"
}