Examine source code of Fake Data Plus

{
  "name": "Fake Data - A form filler you won't hate",
  "short_name": "Fake Data Plus",
  "description": "The most advanced tool for filling forms with fake and random data.",
  "version": "4.12.0",
  "manifest_version": 2,
  "icons": {
    "16": "icons/icon16.png",
    "32": "icons/icon32.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "permissions": [
    "activeTab",
    "contextMenus",
    "storage",
    "<all_urls>",
    "file:///*"
  ],
  "optional_permissions": [
    "notifications"
  ],
  "homepage_url": "https://www.fakedata.pro/",
  "commands": {
    "command-fill-active-field": {
      "description": "Fill active field"
    },
    "command-fill-active-form": {
      "description": "Fill active form"
    },
    "command-fill-entire-page": {
      "description": "Fill entire page"
    },
    "command-manage-active-field": {
      "description": "Manage active field"
    },
    "custom_shortcut_01": {
      "description": "Custom shortcut #1"
    },
    "custom_shortcut_02": {
      "description": "Custom shortcut #2"
    },
    "custom_shortcut_03": {
      "description": "Custom shortcut #3"
    },
    "custom_shortcut_04": {
      "description": "Custom shortcut #4"
    },
    "custom_shortcut_05": {
      "description": "Custom shortcut #5"
    },
    "custom_shortcut_06": {
      "description": "Custom shortcut #6"
    },
    "custom_shortcut_07": {
      "description": "Custom shortcut #7"
    },
    "custom_shortcut_08": {
      "description": "Custom shortcut #8"
    },
    "custom_shortcut_09": {
      "description": "Custom shortcut #9"
    },
    "custom_shortcut_10": {
      "description": "Custom shortcut #10"
    }
  },
  "options_page": "options/index.html",
  "offline_enabled": true,
  "background": {
    "scripts": [
      "js/background_worker.js"
    ],
    "persistent": false
  },
  "content_scripts": [
    {
      "matches": [
        "*://*/*",
        "file:///*"
      ],
      "js": [
        "js/browser.js",
        "js/deferred_promise.js",
        "js/jquery.js",
        "js/css-selector-generator.js",
        "js/integrations/select2.integration.js",
        "js/integrations/angular-material.integration.js",
        "js/integrations/react-select.integration.js",
        "js/integrations/vuetify.integration.js",
        "js/integrations/google-sheets.integration.js",
        "js/integrations/mui-integration.js",
        "js/integrations/fd-public-api.integration.js",
        "js/integrations/google-forms.integration.js",
        "js/foreground.js"
      ],
      "all_frames": true,
      "match_about_blank": true,
      "run_at": "document_start"
    }
  ],
  "content_security_policy": "script-src 'self'; object-src 'self'",
  "browser_action": {
    "default_icon": "icons/icon32.png",
    "default_title": "Fake Data"
  },
  "web_accessible_resources": [
    "sandbox/sandbox.html"
  ],
  "sandbox": {
    "pages": [
      "sandbox/sandbox.html"
    ]
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{a44896c3-223d-4200-abb9-5673fb48ada9}"
    }
  }
}