Examine source code of Reading Comfort Scroller

{
  "manifest_version": 3,
  "name": "__MSG_extensionName__",
  "version": "1.3.0",
  "description": "__MSG_extensionDescription__",
  "permissions": [
    "activeTab",
    "storage",
    "scripting",
    "contextMenus"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "ReadingComfortScroller@example.com",
      "strict_min_version": "112.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "action": {
    "default_popup": "popup/popup.html",
    "default_icon": {
      "16": "assets/icons/icon16.png",
      "48": "assets/icons/icon48.png",
      "128": "assets/icons/icon128.png"
    }
  },
  "background": {
    "scripts": [
      "background/service-worker.js"
    ],
    "type": "module"
  },
  "options_ui": {
    "page": "options/options.html",
    "open_in_tab": true
  },
  "commands": {
    "_execute_action": {
      "suggested_key": {
        "default": "Alt+Shift+S",
        "mac": "Alt+Shift+S"
      },
      "description": "Open AutoScroll Reader popup"
    },
    "toggle-scroll": {
      "suggested_key": {
        "default": "Alt+S",
        "mac": "Alt+S"
      },
      "description": "Toggle auto-scrolling"
    },
    "speed-down": {
      "suggested_key": {
        "default": "Alt+Down",
        "mac": "Alt+Down"
      },
      "description": "Decrease scroll speed"
    },
    "speed-up": {
      "suggested_key": {
        "default": "Alt+Up",
        "mac": "Alt+Up"
      },
      "description": "Increase scroll speed"
    }
  },
  "icons": {
    "16": "assets/icons/icon16.png",
    "48": "assets/icons/icon48.png",
    "128": "assets/icons/icon128.png"
  }
}