Examine source code of Sentence Stepper

{
  "manifest_version": 3,
  "name": "Sentence Stepper",
  "version": "0.3.0",
  "description": "Step through page text sentence by sentence.",
  "permissions": [
    "storage",
    "scripting",
    "activeTab"
  ],
  "action": {
    "default_title": "Sentence Stepper"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "icons": {
    "16": "icons/icon16.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "web_accessible_resources": [
    {
      "resources": [
        "pos-icons/*",
        "other-icons/*",
        "images/*",
        "sstep/styles/panel.css"
      ],
      "matches": [
        "<all_urls>"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "sentence-stepper@example.com",
      "strict_min_version": "121.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}