Examine source code of Reddit Post Font Size

{
  "manifest_version": 3,
  "name": "Reddit Post Font Size",
  "version": "1.0",
  "description": "Adjust the font size of Reddit posts and comments with a slider — nothing else on the page changes.",
  "browser_specific_settings": {
    "gecko": {
      "id": "reddit-reading-helper@ghandiiiiii",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "permissions": [
    "storage"
  ],
  "content_scripts": [
    {
      "matches": [
        "https://*.reddit.com/*"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_start"
    }
  ],
  "action": {
    "default_title": "Reddit post font size",
    "default_popup": "popup/popup.html"
  }
}