Examine source code of Reading Mask

{
  "manifest_version": 2,
  "name": "Reading Mask",
  "version": "0.0.6",
  "description": "Enhance focus while reading with a customizable highlight that follows your cursor, reducing distractions and eye strain.",
  "content_scripts": [
    {
      "matches": [
        "https://*/*"
      ],
      "js": [
        "contentScript.js"
      ]
    }
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "commands": {
    "toggle-mask": {
      "suggested_key": {
        "default": "Alt+M",
        "mac": "Alt+Shift+M"
      },
      "description": "Toggle Reading Mask On/Off"
    },
    "freeze-mask": {
      "suggested_key": {
        "default": "Alt+N",
        "mac": "Alt+Shift+N"
      },
      "description": "Freeze/Unfreeze Reading Mask Position"
    }
  },
  "permissions": [
    "storage",
    "tabs"
  ],
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": {
      "16": "icons/icon16.png",
      "32": "icons/icon32.png",
      "48": "icons/icon48.png",
      "128": "icons/icon128.png"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{87315ad1-f291-4bb0-a3ba-4359ae03c858}",
      "strict_min_version": "58.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}