ReadingRuler

manifest.json

{
  "update_url": "https://clients2.google.com/service/update2/crx",
  "manifest_version": 3,
  "name": "ReadingRuler",
  "description": "A reading aid for pages with wiiiiiiide paragraphs.",
  "version": "4.0",
  "icons": {
    "512": "512.png"
  },
  "commands": {
    "ruler": {
      "suggested_key": {
        "default": "Alt+Shift+3",
        "mac": "Command+Shift+U"
      },
      "description": "Toggles a reading aid for pages with wiiiiiiide paragraphs."
    }
  },
  "background": {
    "service_worker": "background.js"
  },
  "action": {
    "default_popup": "popup/popup.html",
    "default_icon": "512.png"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "js/content.js"
      ],
      "run_at": "document_end",
      "all_frames": true
    }
  ],
  "permissions": [
    "storage",
    "activeTab"
  ]
}