Examine source code of Engram - RSVP Reader

{
  "manifest_version": 3,
  "name": "Engram - RSVP Reader",
  "version": "1.0",
  "browser_specific_settings": {
    "gecko": {
      "id": "engram-rsvp-reader@extension",
      "strict_min_version": "128.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ],
        "optional": []
      }
    }
  },
  "permissions": [
    "activeTab",
    "storage",
    "scripting"
  ],
  "host_permissions": [
    "<all_urls>"
  ],
  "optional_host_permissions": [
    "<all_urls>"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ],
      "css": [
        "styles.css"
      ]
    }
  ],
  "action": {
    "default_popup": "popup.html"
  },
  "commands": {
    "toggle-selection-mode": {
      "suggested_key": {
        "default": "Alt+R",
        "mac": "MacCtrl+R"
      },
      "description": "Enter Paragraph Selection Mode"
    }
  }
}